Linux SMP Round-Up

Dual Minds writes "LinuxHardware.org is at it again and this time they cover three of the finest boards on the market. This review covers three dual processor Xeon boards and they are the only site that ever does Linux reviews (at least on a regular basis). Here's a peak: "First thing is that all E7505-based boards are basically the same on the surface due to the basic features of the chipset. They all have dual processor support, support for dual channel DDR, and support for PCI-X up to 133MHz (to name a few). Once a manufacturer gets their hands on the board though, features can be added or it can simply be left as is." Very in depth and some sweet hardware."

Sort of on topic...

[Suicide]

Since these types of motherboards are aimed at people rolling their own servers, as opposed to buying a prebuilt one.

How many people actually build a server from the ground up, and why, other than price, is it advantageous to do so, instead of buying a complete box? Price shaving shouldn't be a huge concern for a server, since so many other factors figure in more.

Does linux support hypertrheading?

[Billly Gates]

If your throwing enough money around to afford dual Xeon's then hyperthreading support be included.

More information about it is here [aceshardware.com]and you can have virtual dual cpu's per processor. In theory you can have the performance of 4 cpu's with a dual processor setup.

For databases and ERP this could be a very nice and cheaper alternative to expensive IBM and Sun boxes.

My question is does Linux currently support hyperthreading? If not then it may be wise to put off the purchase or buy dual Athlon MP's which are alot cheaper and offer similiar benefits.

FreeBSD 5.0?

[cpeterso]

I would like to see a comparison of Linux 2.4, Linux 2.5, FreeBSD 4.8, and FreeBSD 5.0 on the same hardware. FreeBSD fanatics like to toot their horns, but where are the benchmark results?

btw, LinuxHardware.org is nearly slashdotted, so their Linux server knowledge must not be so great after all.. ;-)

Re:Sort of on topic...

[jawtheshark]

Uhm... Some of us just want an SMP workstation, for the extra punch. I'm not going to pay permium for a server-class machine when I can get a motherboard and a case and assemble it myself (or let it assble by a small shop).
I myself have a Dual AMD Athlon MP 2400+ with a Tyan Tiger board. Works fine, really... It's just a bit, uhm, loud...

Re:How is it a Linux Review without the Distro?

[Dajur]

If your running distros with the "same stuff" installed mandrake should be faster than debian actually. Mandrake is compiled for i586, while debian offers kernels compiled for other cpus(as does mandrake) the rest of the stuff is compiled for i386 for debian if I'm not mistaken.

Re:Does linux support hypertrheading?

[mindstrm]

4 cpus for the price of 2? No.. that's not what hyperthreading is about.

At least, not from what I've gleaned from all the documentation out there.

Hyperthreading is about optimizing the pipelining features of the processor... wheras normally. If the processor knows that 2 instructions are independent of each other, it can run whatever stages of them it has roon for in the pipeline, concurrently. Normaly, preduction and whatnot have to be done, and this is only somewhat effective.

By forcing the OS to treat ti as 2 processors, it now has a clue as to which instructions are definately unrelated, as the higher layer OS has already decided they go to separate processors.

So Hyperthreading is really using 2 virtual processors to better use up the resources of a single processor.. so for some operations it may yield near double the perforamnce, but overall, there is no way this is going to give you the same boost as the equivalent number of processors will.

Yes, linux currently supports hyperthreading. You will see that 4 processors show up on a dual processor xeon system.

Support Issues

[peatbakke]

Support is an argument for and against buying prebuilt systems ...

If you're colocating a server, having a pre-built machine with a tight support contract is pretty crucial. For example, Dell offers a 24/7, 2 hour on-site support guarantee for servers almost anywhere in the continental United States. That's pretty darned handy if your servers are spread around.

On the other hand, if you're able to service the machine yourself within a reasonable time frame, I think it's always better to build your own servers because you have:

- Intimate knowledge of every hardware component in the box. You researched every piece, right? Lots of manufacturers put in weird devices and what-not, and you can never really be sure of what's under the hood when you buy from someone else.

- Spare components on hand. If you're spending the cash on some nice servers, having an extra hard drive, DIMMs, and a network card on hand is pretty invaluable.

- Better upgrade path. Feel free to swap out a motherboard, processor, or SCSI system. No worries about proprietary motherboard or case standards. .. there are other issues than support, of course, but this is just my two cents. :)

Re:Does linux support hypertrheading?

[mrmeval]

I wouldn't know I won't buy intel but tell me something. Is the Athon XP chip also an MP chip?

Kernel says:
Intel MultiProcessor Specification v1.4 Virtual Wire compatibility mode.