Super-Fast Hard Drives 154
codders writes: "An Australian startup company, Platypus Technology, has launched a range of RAM-based solid state drives. These QikDRIVEs can offer sustained data throughput rates in excess of 110MBps and can be up to 8GB in size."
BUS Bandwidth (Score:1)
is a significant percentage of the PCI bandwidth -
which infers that putting two of these in will not
increase your throughput - and even one of these
running flat out will mean other devices such as PCI video and networking may struggle.
I had hoped the quantum leap we benefitted from
when moving from ISA to PCI would last a bit
longer than 7 years, but I suppose thats 3 x
moores law doubling so its not that bad.
Compaq 8500's and Sparc e420's have multiple
busses. If you can afford one of these
puppies you can afford a good platform to run it
on.
Re: (Score:2)
What's the big deal? (Score:2)
Seriously, the present hard drive media has to go. It's the bottleneck of the entire system -and one of the few remaining moving parts in a computer. I'm looking foreward to the day when it's all solid-state.
Re:Using RAMdisks for security, scratch space (Score:1)
#define X(x,y) x##y
Re:Good for video capture? (Score:1)
The drives push about 29MB/sec each on the outside track, so in RAID 0, you'd be pretty much hitting the limit of your PCI bandwidth even at the innermost portion of the disk.
$2500, 90GB of 132MB/sec storage. Since you'd support all the important flavors of RAID, you could sacrifice storage space for redundancy, if you like.. If you're editing video, you probably don't care. For half the price of this QikDRIVE thing, you could get two controllers, each with 10 drives, and make them redundant (RAID 0+1)
Not only that, but you could toss in a motherboard with a couple of 64bit PCI slots, and 1-2GB of memory, and STILL be cheaper than the QikDRIVE.
Re:Before anyone gets carried away... (Score:1)
I definitely see this happening in disk space vs. backup media too. Thanks to Diamond, IBM, et al the capacity of consumer hard drives has left reliable tape backups systems in the dust... Has anyone really worked out how to back up ten or twenty workstations with 60GB of local storage each? A file server with 200GB? Without spending $10,000+ on a tape drive and all day writing to it? With the price of high-end backup devices these days, you could buy all your hard drives over again, maintain them as off-line mirrors, and still have enough $$$ left over for several GB of RAM...
wrong solution (Score:2)
Note that RAM contents already survive reboots; it's the operating system that erases it (some systems take advantage of this fact for fast reboots). If you need power failure protection, you can also back up RAM that sits on the bus with batteries.
So, I think this card is a kludge, something that gives people a quick fix solution to a performance problem. For a quick fix, however, I would prefer a self-contained external box with a SCSI interface.
Re:fast! (Score:1)
I feel old.
Re:Didn't We do This? (Score:2)
And how pray tell, does the *independent hard drive* function in the event of a complete power loss?
The QikCache is 'card only' - when you turn the computer off, it gets wiped. But that's irrelevant, since the thread is specifically about the QikDrive.
The QikDrive is 'card plus external power supply' that allows you to turn your computer off (e.g. to make hardware changes) without wiping your data. It still isn't non volatile (it wipes if the power is cut) and it costs $9840.00 for 8GB. Quantum's pricelist is down right now, but I read it was $500-600 per GB or less than half the price of the QikDrive
The QikData has "mirroring capacity" and the "capability" to transfer to a Platypus HDD with a built-in UPS. This increases the price even more -- the HDD/UPS unit is extra. You also have to load the HDD back to the QikData before you can restore service. Not good.
A nonvolatile Quantum, on the other hand is not dependent on the power. Yank the cord, pull the Quantum, take it cross country, plug it in, just like a HDD. And you have instant high-speed access
So, while I have no strong feeling about either device, I'm hard pressed to see how you give the advantage to Platypus at all, much less $8K worth! No, I'm not being sarcastic. I really am curious why you gave the QikData the advantage. At all.
The Quantum is faster in "transactions/sec" (who cares about 'peak bandwidth'?), cheaper. And can be nonvolatile, straight out of the box without extra wires and components. (You can come crying to us when a technician seeing that the server is powered down feels free to unplug the QikData power cable. A UPS doesn't help, if you're not connected to it!)
_____________
Re:BUS Bandwidth (Score:1)
Re:Why so slow? (Score:1)
Re:Does anyone know (Score:1)
Mat.
Re:Why? (Score:1)
Re:Ooooh (Score:2)
I guess if the motherboard (and operating system) supported it, then you could just GET that much memory (and get rid of the swap file entirely!).
Do they use cheap (and relatively slow) memory for this thing, or what? How much would 8GB of 133Mhz SDRAM cost if you bought retail?
Re:Some more info (Score:2)
The default configurations at those prices are $1538 for 512 MB (upgradeable to 1 GB) and $9840 for 4 GB (upgradeable to 8).
I'm curious; does anyone think that having an external power supply on the RAM drives make them worth the price premium over a software RAM drive?
Hopefully the prices will drop as the next generation of SDRAM factories comes online... ;-)
Why? (Score:4)
I guess the part about an independent power supply is useful. If the power goes out, a UPS is going to be able to power a dinky little card a lot longer than an entire server. However, if your server is under enough load that you need one of these things anyway, you probably have multiple safeguards in place should the power die. You could always keep a hard drive on standby and write your ramdisk to it when the UPS notifies the computer that the power's dead.
So, am I missing something? Is it less practical to cram that much memory onto a motherboard than I thought?
Pricey? (Score:1)
QikDRIVE1 (maximum capacity 1GB) and QikDRIVE8 (maximum capacity 8GB) are available now. Pricing varies depending on configuration. As an example, suggested retail price (ex-tax) for 512MB is $2,500; and $16,000 for 4GB. QikCACHE1 (max. 1GB) and QikCACHE8 (max. 8GB) are available from April 2000. QikDATA8 (max. 8GB) will be available for shipment in June 2000.
Found here [platypustechnology.com]. At today's exchange rate, that's about $1,429 USD for 512MB and $9,145 USD for 4GB.
already in use by gov. (Score:1)
Re:Some more info (Score:1)
Does that mean you lose your data if you unplug its power supply? If so, that would make a UPS necessary, since the smallest power fluctuation could zap your data. But the most likely way to lose data would be moving the machine - and forgetting to back up the drive before unplugging it. DOH! : )
Inefficient for swap (Score:1)
yeah... Until you think... umm, well, if your swap is on ram... Why not just buy more system RAM? and just don't allocate swap. It'll always be faster if the mm layer never has to think about paging out. (Hey, you'll save some ca$h, too.)
"Never trust a Programmer who carries a screwdriver."
Re:Why? (Score:2)
Programs like Premiere and Avid Media Composer don't keep the entire video clips in memory- it would never work with 500MB clips being the routine. Instead, they are stored on RAID arrays or fibre channel-connected Storage Area Networks. Although fast, there is still appreciable time involved when it comes time to render the clips, as the information has to be pulled off disk, processed, and rewritten to disk. With a super-fast (i.e. RAM speed
NVRAM, cache, and speeding disk access (Score:1)
Perhaps someone can do a hardware workaround using an intermediate NVRAM between the SDRAM HD and the hard disk, using principles borrowed from both cache technology and High reliability file systems. But it'll take a bit of work.
You can get pretty good performance with NVRAM, by tightly integrating the OS, the filesystem, and the RAID subsystem. Hop on over to NetApp's Technical Library [netapp.com] to read how they did it. In particular, check out File System Design for an NFS File Server Appliance [netapp.com] which discusses how the Write Anywhere File Layout (WAFL filesystem) knows (and can take advantage of) how the RAID subsystem works. The NVRAM is mainly used to speed up write performance. They've also got some interesting bits on how the RAM cache works. It gives decent performance, even though NetApp caches tend to be small by modern standards.
James
A nifty confluence of technologies (Score:1)
Re:What's the big deal? (Score:1)
Yes, but having a swap file doesn't solve your out-of-memory problem, as you will encounter the exact same situation a bit later, when you run out of swap space. It does delay the onset of the problem for a while--on the other hand, during the time your machine is out of RAM and swapping, your machine's performance will be so poor that it might be better to have it just Panic immediately and be done with the crisis.
(by Panic I don't mean crash--rather, the system could initiate some kind of emergency procedure for freeing up RAM... maybe by finding the largest non-critical process and killing it. Which processes are considered "non-critical" is left as an exercise for the Sysadmin)
Re:First (Score:1)
Re:BUS Bandwidth (Score:1)
fast! (Score:1)
Re:Application Structures, Volatility, Scale (Score:2)
Again, this argument just dosen't hold salt.
Yes, but is it worth it's water?
While I'll agree that in general, these devices have limited usefullness, there ARE cases when an application developer can better guess at important usage patterns than can a caching algorithm.
For example, a given application might be optimizing indexes when there is no demand on it. When the application would be otherwise idle). In such a case, the caches would always be full of arbitrary indexes that are being optimized.
However, when a user actually attempts to use the application, 99 out of 100 times a particular set of pages might be called on first. In this case, it would be nice if you could guarantee that these pages could be accessed with minimal latency.
Having said this, I would, in general, rather have the directly addressed RAM (standard memory) rather than the SCSI bus RAM in my system. Even if there is an advantage to RAM drive optimizations, I'd prefer to have the flexibility of RAM drive software to turn segments of the directly addressed RAM into easily reconfigured RAM drives rather than inflexible SCSI bus RAM drives.
I also think argument that dropping a RAM drive in to give a boost to existing applications that this poster makes best [slashdot.org], I think, is a good one. But, again, a RAM drive defined in software would be better here.
-Jordan Henderson
Using RAMdisks for security, scratch space (Score:1)
You probably don't count Win 95/98 as modern (:-), but I actually do use a small ramdisk as scratch space for security applications where I don't want the data written to a disk drive. (There is still a risk it'll get written to swap space, but I'm not doing anything at that level of paranoia :-)
/tmp on that would do as well. Unix /tmpfs file systems would do a better job of that - they avoid writing stuff to disk until necessary, on the assumption that you'll discard most of it pretty soon, which speeds up applications like compiles more effectively than normal caching strategy which assumes you're saving something to a disk because you actually *want* it to be written to the disk.
It's also useful for stashing web or mail downloaded zip files where I don't have to worry about cleaning them up later, but having a big enough disk drive with a
Re:Nice data throughput (Score:1)
Re:Why so slow? (Score:1)
They run off of the *other* 64-bit 66MHz PCI bus, of course.
Come on, if you're going to spend $8000 on memory, you're probably going to have more than one PCI bus. (Of course, you're probably also not going to have a voodoo 2 setup, but that is a different issue).
Re:Ooooh (Score:1)
After all thats all it is.
In fact the RAM would almost certainly be cheaper, and a better investment in the long run.
Re:Why? (Score:1)
Required Microsoft Bashing Post (Score:4)
"The hardest thing to understand is the income tax." - Albert Einstein
Re:Some more info (Score:1)
I'm sure I can exceed 110MBps with an Adaptec 39160 SCSI card (64bit, dual channel) and 2 drives in a stripped RAID. For less than half of the price for the 8GB version. Using 2 18.2GB 15,000rpm Ultra3 SCSI drives too!
--
Re:Eliminating Latency is the big win (Score:1)
It is nice to see this technology trickle down into the PC world, though. Now we just have to wait for PCI's successor to see some real throughput improvements.
What goes around ... (Score:2)
Now we have these QikDRIVES capable of holding up to 8GB. Finally, enough space to be useful. But because they are using ECC SDRAM, the prices are going to be too expensive for all but the most serious of consumers. It's generally been accepted that hard drives are slower than RAM, so why not use cheaper RAM that runs at, say, 60ns (like the old EDO RAM)? We would still probably want to use ECC or something similar for data integrity. Would this cut the price sufficiently to make it attractive for the average person? Obviously, it would still cost more than a conventional hard drive, but hopefully not nearly as much as the current line of QikDRIVES.
Now I'm not saying to dump the existing line, since they will still be attractive to those who need the high performance. I'm just thinking of how to reduce prices. And over time, the prices on these things can be expected to drop anyway, perhaps even making them commonplace. Does this sound plausible?
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Re:Why? (Score:1)
If it *is* non-volatile, then the answer should be obvious.
--
A mind is a terrible thing to taste.
Re:Ooooh (Score:1)
Even if they're volatile... (Score:1)
I would think a reliable UPS and an "old-fashioned" drive on standby would be a pretty sure bet. You'll need a physical drive to load up your Qikdrive at boot time, and save out at shutdown, so that thing will already be spinning when the power cuts out. Then your only worry is that you can copy 8G before your UPS fails
Re:"Hard Drives" (Score:1)
Solid State Disks (Score:1)
Hardware == Hard drive? (Score:2)
Re:Instant on- (Score:2)
For me the main thing is having enough *reliable* space to store my digi-junk.
For you the solution would probably be a four letter word: cdrw.
Re:Wow! Something totally new! (Score:1)
Re:Required Microsoft Bashing Post (Score:1)
Round the circle again (Score:1)
Most of those died off when 32/64-bit addressability started getting more commonplace, I guess it's about time for that to happen again as M$ isn't going to have Win64 working for years.
Instant on- (Score:1)
-
Before anyone gets carried away... (Score:5)
The Platypus overcomes the HDD's primary liability (read/write latency) at a serious cost to the HDDs primary function: reliable storage. Note that it doesn't even have an on-board battery. It simply has a separate external Power supply and (optional) UPS
While a UPS is wonderful for keeping my system running, it's much less reliable than it needs to be if an outage (or office idiot kicking the plug out) means I lose *all* my data (sales for the day, etc.) In a sense, the platypus drive is not much stabler than having 8GB of system RAM and *no* HDD ["not much" is relative. The MTBF of a UPS is orders of magnitude less than a good HDD)
I doubt the usual high reliability filesystems could maintain a RAID/HA type redundant backup to disk precisely because the RAM HD is so much faster than the disk. It would be like having a scribe backing up your HD to quill-and-scroll -- the more you utilize the tremendous speed of the RAM HD, the farther behind the disk will fall (and thrash).
It's a nice product (though hardly a new idea), but I see it having limited application (e.g. as a HD accelerator in some server applications)
Perhaps someone can do a hardware workaround using an intermediate NVRAM between the SDRAM HD and the hard disk, using principles borrowed from both cache technology and High reliability file systems. But it'll take a bit of work.
Is there already a solution out there? Or is this essentially just a giant unidirectional HDD cache, good for serving up data faster than an HDD, but not good for critical rewritten data?
_____________
Kinda Spendy (Score:1)
But geez what a great swap partition it would make!
Re:"Hard Drives" (Score:1)
Re:Some more info (Score:1)
--
Jesse Tie Ten Quee - tie@linux.ca - highos@highos.com
http://highos.dhs.org
Ramdrive? (Score:1)
Re:Why? (Score:1)
Re:Good for video capture? (Score:2)
Re:What's the big deal? (Score:2)
Re:Why? (Score:1)
Motherboards have only so many memory slots. 256MByte DIMMs are the cheapest per MByte, 512MByte DIMMs are still reasonably priced per MByte. Gbyte DIMMs are way more expensive. 2GByte DIMMs are insanely expensive (SGI sells them for their Octanes, I don't know who else does).
Any real advantage under linux? Any benchmarks? (Score:1)
On other OSes, perhaps it would be advantageous. But as to the suggestion that it could be used for virtual memory (this was on their Web page!), you have got to laugh. Does it make any sense to anyone? I mean why go through the kernel as a file operation, go through the PCI bus, get the stuff from RAM, bring it back and THEN turn it into a page; rather than using actual RAM?
Has anyone actually done benchmarks on the supposed applications of these things (say, webserving under Linux)? I could find no benchmarks on their web page. It seems to me that it might be 10 or 20 per cent faster, but given that the bottleneck is likely to be the network and not the machine (and besides, it would be better value to simply *upgrade* the machine), why bother?
Startup company? Risky moves..... (Score:1)
Can you say...OVERKILL? (Score:1)
-Slayback
P.S. Does anyone know of a website that is running off of one of these? Just curious.
Re:Wow! Something totally new! (Score:1)
-Slayback
Re:Eliminating Latency is the big win (Score:3)
I just remembered this old Metallica song. . .
I've used a prototype (not from Platapus) (Score:4)
The biggest problem with 32 bit machines is not the 32 bit int, which is really sufficient for most things, it's the inability to address more than 4 gig of memory. This provides a relatively clean solution to that problem by using this device as swap. The burning question, of course, is performance... how much worse is it than on board memory?
The answer is, of corse, it depends: If you are in a single process enviroment, the time it takes to swap pages is somewhat killer, because the machine justs sits on it's ass while the DMA moves the block. Now, don't get me wrong, it's a lot better than disk, but it's not like real meory.
However, on multi-process machines like servers, it's great. There is a delay for the page swap, but the other processes keep the cpu busy and the DMA keeps the bus busy. Since throughput is more important than response time, this is almost as good as onboard ram. But, you say, this is MORE expensive than real RAM? not really... for an app like this, it will be an smp machine anyways, and the difference in cost between comodity x86 parts and a 64bit+8gig-uberboard setup from a proprietary vendor is so great that you could buy one of these things with the spare change. This could easily save many tens of thousands on certain types of server projects.
already available (Score:1)
Re:Some more info (Score:1)
Just because you have a pipeline that can support it doesn't mean you have the technology to sustain that throughput.
Harddrives are a VERY old technology. I mean seriously!! The most vonerable part of the computer is the Harddrive, PowerSupply, and CPU Fans (if you're x86 anyways)..
I can't wait until computers are 100% solid state. Moving parts increase points of failure.
This solid state drive is neet, but looks WAY too risky to me to stick in a production server. I mean if the only way these things are makeing sure they don't loose the data is to keep power to it all the time, COME ON! We have had the ability to do 8GIG Ram Drives for a LONG time now!
Seriously, what if the "PCI CARD" needs a good-ol-fashioned reboot?? You can't tell me this company GAURENTEES a 100% UPTIME on their "NEW" PRODUCT.
I noticed how they recommend it for "web Proxies, Secondary DNS Servers,
Why can't someone come up with a USABLE product?? Like a 8GIG SolidState Drive with NVRAM instead of SDRAM
Why hasn't anyone persued the NVRAM option??
Ryan
Had an idea on the lines of this about 6 years ago (Score:1)
A hd that had approx the same size ram cache in
the same box.
On boot.. the os loaded on the harddrive would load
itself into ram and would run from there... meanwhile
backing itself up to the hd as files were changed etc.
Unfortunately I had neither the time, money, nor experience
and knowledge to build a microboard that would handle
those transactions and report to the MB as a standard hd.. *sigh*
The things we come up with that are implausible to
one's current abiltities/situation... *shrug*
Anyone need an intelligent, intuitive, dreamer
for their R&D dept? I work like a bastard, am
fantastic for company morale and have some of the
best ideas on a constant basis...
(Sucks waking up at 2am with a fantastic idea and
having no one intelligent around who can follow you
past the first 10 words out of your mouth. *sigh*)
Anyway.. Party on!
Re:Some more info (Score:1)
Ryan
PS. Not like I am either.. but still...
I've been thinking about this for years! (Score:2)
Re:Why? (Score:1)
Imagine you developed a Windows NT system to keep development simple (yes some things are simpler on Windows), then your system becomes a success. More of a success than the system can handle. Your choices are:
Which solution costs less and get finished faster?
I look forward to the day when standard hard drives are done with RAM of some flavor. What's all this silly business with spinning disks and moving parts? Feels kind of archaic doesn't it?
Sure I think I'm right. If I thought I was wrong, I'd change my mind.
Re:Eliminating Latency is the big win (Score:1)
I just remembered this old Metallica song. . .
Re:If it costs $600, I'll have one. (Score:2)
The problem is keeping the head aligned with the track on the disk. This is difficult enough with a single active head. As soon as you introduce multiple active heads, you have the problem of keeping multiple heads independently aligned with their tracks. Putting two heads on a single positioner arm isn't going to work because of thermal expansion/contraction of the positioner arm and mechanical errors with alignment of the positioner arm and the disk platter. You need independent positioner arms, each with its own servo system and read/write electronics. This is very expensive. Multiple heads on a positioner arm and head per track disks used to be common in high-performance disk drives when track densities were much lower than today. I used to use a computer that had a 5 MB head per track disk drive, it used up a whole 19" rack.
Read/Write ratios, Peak/Average, Falling Behind (Score:1)
The caching lets you write to the disk in reasonably optimal order, laying down long bursts of stuff on the same track instead of seeking and rotating in between them. Of course, most modern disk drives too that also, though last I checked the caches were typically small, like 1 MB, though that may be enough for many applications. Having a substantially bigger cache on your computer means that you're much more likely to hand the disk drive orderly stuff to write, and wasting less interface bandwidth on reads and on idle time.
PCI?!?!? BAH!!! (Score:1)
When volatile storage is acceptable (Score:1)
If the database goes stale while a server reboots, it doesn't matter if it is volatile or not.
No way to get 8GB of SDRAM for $600. (Score:1)
-slayback
With the current market... (Score:1)
-slayback
Re:"Hard Drives" (Score:1)
Re:Why so slow? (Score:1)
John Wiltshire
Re:It's about time (Score:2)
It has already happened. The heads, tracks and cylinders that you see in the BIOS setup screen on a PC have no basis in reality. That is just a software compatibility kludge for PC operating systems. If you look at the SCSI specification, you will find no mention of heads, tracks and cylinders, the disk is addressed as an array of logical blocks. IDE drives can use logical block addressing, similar to SCSI, or heads, tracks and cylinders. Due to the use of techniques such as Zoned Bit Recording (ZBR), the number of sectors per track is not a constant. The IDE drive translates the physical sector address provided by the CPU to/from an internal sector address that reflects the actual layout of the drive. I've seen SCSI drives with larger sector sizes but they are rare.
Why does it require THEIR sdram memory? (Score:2)
Re:Good for video capture? (Score:2)
They tried it as scratch-disk for Photoshop with, IIRC, a 2 or 3 hundred meg file and said it was like working in RAM.
*sigh* Yet another thing for my wish-list.
---
"When I was a kid computers were giant walk-in wardrobes served by a priesthood with punch cards."
Application Structures, Volatility, Scale (Score:2)
There are also scaling issues - motherboards always have some limit on capacity, whether it's address lines or card slots or whatever. With Ultra-Mega-FooBar-SCSI, you can hang 8-16 of these things on the bus if you need to. Living on a bus lets you design boards for your specific application, and isn't limited by the design tradeoffs and compatibility requirements of a general-purpose computer, just by the size, power, and cooling of a shoebox or 1-2U and the creativity of the designer. Can *your* desktop machine address or even hold 8GB of RAM? Mine can't.
Some more info (Score:4)
$1,538 for a QikDrive1 with up to 1GB storage.
$9,840 for a QikDrive8 with up to 8GB storage.
The QikDrive is on a PCI card, but has its own internal power supply for data security. Presumably to keep the drives from being wiped by a system power failure.
They support between 15,000 and 20,000 I/O transactions per second (versus 200-300 for Winchester-style drives)
Re:Why? (Score:2)
Does anyone know (Score:2)
Just think how fast Metallica MP3's can be downloaded to these babies! tcd004
Here's my Microsoft [lostbrain.com] parody, where's yours?
Actually, it's quite cheap. (Score:2)
Re:Nice data throughput (Score:2)
This thing would seriously rock for video capture. I'm currently having to capture video in compressed form to avoid hard drive bandwidth issues.
Old stuff (Score:3)
Check out solidstate.com, mti.com, etc. they have much better solutions than putting a card into your computer.
I checked out SSD's last year to see about SAN integration, but the cost if VERY prohibitive. i.e. 90k for a 4 gig disk with a fibre channel connections (of course that was battery backed up, disk backed up, etc). If you are running a big data base/warehouse they can become very useful, they appear to the system as a regular drive, no drivers, etc. I know of a couple of companies who do a raid set over multiples of these (think 10x4 gig striped SSD's to do big database billing then think price).
Legato NFS Accelerator Boards for Suns (Score:2)
Re:I've been thinking about this for years! (Score:2)
Of course, this would have to be a 64-bit architecture to be able to address that much memory, and you would need an OS that supports that much memory.
Re:Some more info (Score:2)
Oh, good! I was worried they would be expensive or something :^P
Why so slow? (Score:2)
I think that at very least they should be able to run at the 533MBps maximum speed provided by 64-bit 66MHz PCI.
Re:Wow! Something totally new! (Score:2)
Re:Application Structures, Volatility, Scale (Score:2)
Again, this argument just dosen't hold salt. If you want to have something that fast, then just provide lots of RAM and your OS will use it as a cache. There's literally NO reason to use a ramdisk except as an initial boot loader if you're using a modern operating system.
Re:I've used a prototype (not from Platapus) (Score:2)
Actually Intel based systems can addres up to 64 GB of memory using Physical Address Extensions (PAE) for 36-bit addressing.
Hardware needs to be 64-bit compliant and/or support Dual Address Cycle (DAC) to address memory above 4 GB.
"because the machine justs sits on it's ass while the DMA moves the block."
If you are using a busmaster PCI device (which any SCSI or Fibre Channel card is) the card itself does the DMA. Most modern operating systems support non-blocking I/O. This means that a read/write call can get a pending response. The caller can than go about other things or wait on an event to signal the I/O completion. If the caller waits, the OS can run another thread or process until the event is signaled. If the caller doesn't wait, it can still be interrupted when its quantum expires.
I have worked on a Fibre Channel/RAID adapter that blows this thing out of the water. 110 MBps? In vanilla direct connect mode (no raid), our card did 190 MBps and 20,000 I/Os per second. With RAID and a 64 MB cache, we can beat that. 8GB? We worked with 1TB to 10TB databases. By putting only up to 8GB on one PCI card you are really limited. 64-bit, 66 Mhz PCI supports up to 528 MBps. Five of their cards on one bus would give you only 40 GB at a transfer rate of 105.6 MBps per card. You can add busses but that isn't cost effective. On other hand, you can put nearly unlimted storage on one of cards. For the best speed you can spread it out over multiple ports (our card has two) and multiple cards. 3 cards on a 64-bit, 66 Mhz PCI bus can still hit 176 MBps each (2 cards can hit 190 MBps each) with MUCH more storage.
This thing is too small and too slow for their target market of enterprise computing.
Re:Why so slow? (Score:2)
Good cache managment on a RAID card can get this kind of performance per RAID drive using much less RAM. You computer doesn't have 64 MB of L1, 2, or 3 cache, does it?
Re:Ooooh (Score:2)
Re:Using RAMdisks for security, scratch space (Score:2)
But as for the scratch space, I believe there is a function to request a block of memory never go to swap. I know linux has this feature, I thought windows did too.
Good for video capture? (Score:2)
My main concerns are:
A) Is this here to stay, or is it going the way of the SparQ?
B) Is it going to be cost-effective? Granted an Art Director like myself can just get the company to pay for the drive as part of a new system or upgrade, but many freelancers would have trouble with a super expensive drive. . .
C) Are they really going to be worth using, or am I going to have constant trouble getting the damned things to work on my Operating System(s) of Choice[tm]?
Eliminating Latency is the big win (Score:4)
Be sure to use a good UPS with the things, and make sure your powerfail shutdown procedures work well.