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Overclocked Memory Breaks Core i7 CPUs
Posted by
kdawson
on Tue Oct 07, 2008 03:41 PM
from the chip-has-potential dept.
from the chip-has-potential dept.
arcticstoat writes "Overclockers looking to bolster their new Nehalem CPUs with overclocked memory may be disappointed. Intel is telling motherboard manufacturers not to encourage people to push the voltage of their DIMMs beyond 1.65V, as anything higher could damage the CPU. This will come as a blow to owners of enthusiast memory, such as Corsair's 2.133MHz DDR3 Dominator RAM, which needs 2V to run at its full speed with 9-9-9-24 timings."
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Inside Intel's Core i7 Processor, Nehalem 146 comments
MojoKid writes "Intel's next-generation CPU microarchitecture, which was recently given the official processor family name of
'Core i7,' was one of the big topics of discussion at IDF. Intel claims that Nehalem represents its biggest platform architecture change to date. This might be true, but it is not a from-the-ground-up, completely new architecture either. Intel representatives disclosed that Nehalem 'shares a significant portion of the P6 gene pool,' does not include many new instructions, and has approximately the same length pipeline as Penryn. Nehalem is built upon Penryn, but with significant architectural changes (full webcast) to improve performance and power efficiency. Nehalem also
brings Hyper-Threading back to Intel processors, and while Hyper-Threading has been criticized in the past as being energy inefficient, Intel claims their current iteration of Hyper-Threading on Nehalem is much better in that regard."
Update: 8/23 00:35 by SS: Reader Spatial points out Anandtech's analysis of Nehalem.
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The What of the What? (Score:5, Funny)
This will come as a blow to owners of enthusiast memory, such as Corsair's 2.133MHz DDR3 Dominator RAM, which needs 2V to run at its full speed with 9-9-9-24 timings."
I'll just stick to the mathematics of quantum field theory. Kids these days and their crazy machines!
When we asked Pooh what the opposite of an Introduction was, he said "The what of a what?" which didn't help us as much as we had hoped...
Not news (Score:5, Funny)
Re: (Score:3, Interesting)
Well the downsizing of the cpu transistors make them "faster" but also more fragile.
To be more specific overvolting is not a problem for the transistor itself but it is a problem for the interconnections due to the effect of Electromigration http://en.wikipedia.org/wiki/Electromigration [wikipedia.org].
The interconnections of latest CPUS are so thin that +0.15 could mean a lifespan cut of 50% or more. While higher values could mean a lifespan of months instead of years!
Its true that overclocking was always said to be a dan
Re: (Score:3, Interesting)
Actually if you apply too much voltage to the gate of CMOS transistor you can exceed the breakdown voltage of the gate oxide which, as I recall, scales with oxide thickness which itself scale inversely with process node. So actually "overvolting" can be a problem for the transistors, although I admit I don't know if electromigration or oxide breakdown dominates as a failure mechanism given the minor voltage changes we are talking about here.
Re:Not news (Score:4, Insightful)
Let me say this slowly:
If the factory makes it that way, it is not overclocked.
Parent
Overclocking (Score:5, Interesting)
Some of the OC memory is hard to install (Score:3, Interesting)
Re:Some of the OC memory is hard to install (Score:5, Informative)
Yes and No. The JEDEC specifications say that DDR2 must be able to handle UP TO 2.3 volts before incurring any PERMANENT damage. However, 1.9v is considered the max when stability is of concern and anything over that is not guaranteed to work (properly).
DDR3 is specified to work at 1.575v, but able to withstand up to 1.975v .. Again, no guarantees it will function properly, but (according to the standard) shouldn't fry it. Now, other factors do come into play such as less life, more heat generated, more power used, etc.
The JEDEC specification is for memory modules. What Intel is saying is their processor will (likely) get damaged any more than 1.65v.
Parent
Out of Spec (Score:5, Insightful)
Considering that so many memory modules require running out of spec voltages to operate properly, while the Intel CPU requires voltages within spec, it would appear to me that the memory makers are turning out bad memory.
Maybe instead of requiring users ramp voltages up to CPU damaging levels, they should fix their chips? Now that Intel has brought the memory controller into the CPU, that they have tighter tolerances for the voltages does not surprise me.
Integrated memory controller. (Score:5, Insightful)
Given the boost that on-die memory controllers gave to AMD, back when they adopted them, I suspect that the tradeoff will still be worth it. On the other hand, I strongly suspect that there are going to be some very unhappy cries of "WTF! How could RAM voltage kill my CPU?" from adventuresome kiddies unfamiliar with the implications of this change. Warning stickers aren't going to deter them.
Blazing 2 MHz Memory! (Score:3, Funny)
Re: (Score:3, Funny)
It's just a matter of time... (Score:5, Funny)
Bonus points if they're LEDs.
Re: (Score:3, Interesting)
Armed with the knowledge that the PN junction voltage drop of a Diode is 0.7v, and either no forethought, or no knowledge beyond that at all in the hardware domain, you have managed to make a very absurd statement (no offense.)
I'm not going to get into the myriad ways that this is absurd and impossible, but lets start (and end) with the fact that you can't just start soldering things on a board when things are clocked in the Gigahertz range from a theoretic
Intel can't do split volts on the cpu and ram like (Score:3, Insightful)
Intel can't do split volts on the cpu and ram like amd boards and older Intel boards can do??
Will any other stuff like this show up in QPI 2+ systems with the QPI bus?
Just wait... (Score:5, Insightful)
A few months after the initial release of desktop i7 chips, they'll release a chip that can handle up to 2.0V DDR3 running at up to 2.4 GHz. The CPU will cost $1500, have an unlocked multiplier, and require a $300 motherboard, a $200 power supply, and a $100 cooling device to function with the out-of-spec enthusiast RAM. Gamers with more money than sense will eagerly shell out for it, and blame Nvidia's drivers when they only get an extra 1.3 FPS over JEDEC-compliant mainstream CPU/RAM configurations.
Re: (Score:3, Informative)
Re:About overclockers: (Score:5, Insightful)
Parent
Re:About overclockers: (Score:4, Funny)
If they can get a stock four-banger with nitrous feed and twin turbos bolted on to not slip the clutch until the checkered, they're doing pretty well. I'd expect that setup to fly apart closer to the green.
Parent
Re:About overclockers: (Score:5, Informative)
You are missing a point here. there are ram chips out there that are designed to run with more voltage then 1.65. So you do not even need to overclock for this to happen.
for example
OCZ Platinum 2GB (2 x 1GB) 240-Pin DDR3 SDRAM DDR3 1333 is a 1.8v standard. that's NOT overclocking
I agree overclocking and you break something your own problem but this product can't even use some decent ram as its stated to be used without blowing the CPU. At that point I would want my CPU replaced thank you,
Parent
Re:About overclockers: (Score:5, Informative)
Parent
Re:About overclockers: (Score:5, Informative)
1.8 volts for DDR3 memory is severly out of spec.
The nominal voltage is 1.5. Chips nominally operating at higher voltages are of *LOWER QUALITY* than chips operating at the proper 1.5 voltage.
The ability to increase voltage to offset more aggressive timings than the memory supports is the real issue. At that point you are getting no real performance improvement and the real possibility of random bit flips + additional wear on the memory/northbridge/cpu.
DDR3 and CPU caches are all about bulk data transfers and have zero to do about latency. Whatever silly gains you think you are getting by playing with timings are hidden by the nature of the hardware.
Parent
Re:About overclockers: (Score:5, Interesting)
No, they're lower binned parts that couldn't make "enthusiast" OR normal speeds at 1.5 volts.
They crank up the voltage and re-rate them at a higher speed, and slap on ridiculous cooling (heat spreaders, heat pipes, built in fans).
They KNOW these pieces will fail at high rates, so they jack up the price and call it gamer/enthusiast RAM. When the return rates start to drop off, they start issuing rebates to move remaining stock.
Parent
Re:About overclockers: (Score:5, Informative)
Parent
Re: (Score:3, Informative)
Probably because the IO voltage rating of the Intel technology for the transistor is lower than AMD. Intel CPU is on a 45nm process and AMD a 65nm process, usually bigger process are more tolerant. If Intel IO run at 1.5V we can suppose there are 2 reason for the limit of the ram.
First if the IO go beyond the 1.5V you can either break the protection diode on the cpu pin or inject current on the power line for the IO on the chip. That part is bad because it force the power supply to compensate for that and t
Re:About overclockers: (Score:5, Insightful)
You're missing the point here. If there are RAM chips out there that are designed to run with more voltage than 1.65v then those RAM chips are not designed to the JEDEC standard. Legally, they probably shouldn't even be able to sell them as DDR3 since DDR3 is a JEDEC standard and the parts on non-compliant. Of course, most of the memory manufacturers do this anyway, and since they are part of JEDEC nobody complains too loudly...except when things don't work, of course.
OCZ Platinum 2GB (2 x 1GB) 240-Pin DDR3 SDRAM DDR3 1333 is a 1.8v standard. that's NOT overclocking
But it is over-volted.
Parent
Re: (Score:3, Insightful)
If you push the limits of a device, you deserve what you get. Maybe good and cool, maybe broken shit.
Considering an entire subset of the industry exists dealing exclusively with parts designed to run 'faster-than-spec' I'm more inclined to lay the blame on Intel. They should know full well by now that the enthusiast market drives a lot of personal buying decisions further down the food chain...
Remember when Tom's Hardware broke this story? [zdnet.com]
If you can't release components that will run with existing kit, well someone is going to get the short end of that stick... And when it's the high end consumers, well O
Not really (Score:3, Insightful)
They deserve to live with their results, be those increased performance or broken components. Saying they deserve busted components is like saying someone who soups up their car deserves a blown motor. Both endeavors, done correctly, can boost the performance of the tool in question. It's not hurting anyone, so why the sour grapes? Never were quite able to get the CPU overclocked so you want everyone who tries to fail?
Re:About overclockers: (Score:5, Informative)
Push what limits?
You're not pushing a cpu, it was designed to run faster! Just bined lower.
You're not overclocking overclocking ram at 2v. Its designed to run with that voltage!
This isn't an overclocking issue, its a design flaw by Intel. Not our fault you can't see the forest for the trees.
Run a CRC on your brain, sparky, you dropped a bit or two.
The Nehalem CPU is designed to run at JDEC Spec of 1.5V, but can handle 1.65 without being binned. Yes, the RAM is designed for 2V, but the CPU wasn't - use the RAM, take a chance on killing the CPU and voiding your warranty.
60nm parts have 25% more area in which to absorb electrons and 25% more dielectric between elements than a 45nm part, so of course they could handle more voltage without damage. It's a design flaw in material physics, not the processor.
Parent
Re:About overclockers: (Score:5, Funny)
So much for intelligent design.
Parent
Re: (Score:3, Informative)
60nm parts have 25% more area in which to absorb electrons and 25% more dielectric between elements than a 45nm part, so of course they could handle more voltage without damage. It's a design flaw in material physics, not the processor.
And that looks like a fault in your calculation. 45^2 = 2025, 60^2 = 3600. 3600/2025 = 1.78. So 60 nm parts have 78% more area.
Re:About overclockers: (Score:5, Informative)
Parent
Re:About overclockers: (Score:5, Insightful)
You're not pushing a cpu, it was designed to run faster! Just bined lower.
This is a brand new CPU. I don't think they're worried about the low-end market just yet, and are labeling them as high as they can.
Parent
Re:About overclockers: (Score:5, Informative)
by adjusting the RAM voltage, you are also the voltages on the input pins of the processor. Overvolting an I/O pin can cause latchups, which basically is a short circuit.
Parent
Re: (Score:3, Insightful)
and it's not as if the CPUs that are overclocked weren't designed to do so.
I can remember a time when connecting nodes on circuit boards with a graphite pencil was a good way to increase multipliers and voltages. And it wasn't that long ago, these new fangled extreme processors and enthusiast motherboards are a pretty new thing. So I guess this doesn't surprise me too greatly, I'm sure a lot of minds at Intel Corp. remember the good old days when they were the ones OC'ing chips straight off the assembly line to sell as premium stock and motherboard settings were locked down like G
Re:About overclockers: (Score:4, Funny)
Still running that Dell eh?
Parent
Re:About overclockers: (Score:5, Insightful)
That extra 20fps won't make your penis any larger.
Sorry..
Parent
Re:About overclockers: (Score:5, Funny)
I'll be the one laughing at the pathetic excuses you make up when I still kick your ass.
Parent
Re:About overclockers: (Score:4, Insightful)
Actually, this is still logically intractable. The best you can do is run it and wait for it to fail. If it doesn't fail, all you've shown is that...it didn't happen to fail. That isn't to say that it WOULDN'T have failed if you had run it for one more cycle, just that in your test space, you didn't get it to fail.
Short form: try to prove that something DOESN'T fail is trying to prove a negative, which doesn't work.
This is what you were getting at, obviously. I just wanted to clear it up for other people. :)
Parent
Re:About overclockers: (Score:4, Informative)
Because Intel and other chip fabricators can run lower level tests on the actual electronics of the chip than a nerd on the internet can.
They can physically inspect the chips from a given batch.
The most 99% of overclockers do is run a program to calculate Pi to a hojillion places over night.
Intel and other chip fabricators have set tolerances for the electronics. If a part falls within the tolerances, it is deemed good, if it doesn't, it is deemed bad.
For Intel and other fabricators, if a chip passes physical inspection, and a batch of them meets or beats the MTBF, they are considered good. If they pass physical inspection, but are statistically deviant from the MTBF (in a bad way), the batch is bad.
In a processor, logical failure is often the end result of physical failure, but physical failure usually does NOT end in logical failure.
You CAN prove that any given processor is logically reliable if run all possible valid input sequences on it. This is beyond astronomical (but not infinite, since we're talking about a logical level, and there are a finite number of logical states to any processor, along with a finite number of valid inputs).
You cannot prove that a processor is physically reliable, since the processor physically changes as you use it. This is why we have tolerances. Unfortunately, we want more performance, which means smaller fabrication processes, which means tighter tolerances, which means lower yields.
Parent
Re: (Score:3, Insightful)
"Among other things"?
Other things like the fucking initial design and engineering process? The processes, parts, and materials we use all have known physical limitations.
We know what the theoretical top speeds are when we design processors. We know that variations in the manufacturing process often alters the capabilities of a design in the real world.
It's not like baking a fucking cake and then being surprised at how delicious it is. We design, manufacture, and test to make sure we get our expected deli
Re: (Score:3, Informative)
A properly written software test is what, exactly?
Something that would cause the chip to fail physical inspection may not show up on any software test, especially if it only caused the part to be rebinned to a slower speed.
A CPU can be operating incorrectly in countless ways. Whether it shows up on one specific logical test under certain physical conditions, or whether it continues to show up or not after a certain amount of time is another issue entirely.
Go to school, or go back, or major in something oth
Re: (Score:3, Insightful)
Methinks someone doesn't know what DDR stands for...
Re: (Score:3, Funny)
Warning! May contain nuts!
If you know what I mean...
Re: (Score:3, Interesting)
Buy DIMMs that work at lower voltages because they use smaller processes or buy motherboards that separate the refresh power circuits from the data circuits on your RAM. It's doubtful that the data lines need 1.8 or 2.1 volts or whatever.
Re: (Score:3, Informative)
No, you're right. In rare cases an overclocked Celeron performed better than the standard-clocked Pentium 3 of the same nominal speed on most benchmarks. It's been a long time since the Pentium 3 and that generation of Celerons, though, and it usually wasn't worth doing even then.
Re:I don't get memory overclocking (Score:4, Interesting)
Parent
Re: (Score:3, Informative)
Back in the day of DDR1 you'd be right, but these days the timings on the RAM are much larger but this isn't necessairly a bad thing. DDR3 runs much faster then it's older brothers and so the actual latency times are quite comparable.
The bigger numbers in timings mean a whole lot less when the clock is ticking that much faster :)
Re: (Score:3, Funny)
Says Intel, dipshit.
This is old news, by the way.
Re: (Score:3, Informative)
The data and address lines are connected. No amount of design can change that.