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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."
I'll go read the article now.
Old people fall. Young people spring. Rich people summer and winter.
If you need hardware like this, then you need Support. That's what attracts people to Sun (and now Dell, for instance). And if you need support, you'll take whatever board your System Integrator uses in their boxes.
To wit:
If you need this, you'll buy it from someone.
If you buy it from someone, you have no choice of HW.
Thus, this review is useless.
I want to delete my account but Slashdot doesn't allow it.
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.
Linux does support hyperthreading. 2.4.20 recognizes four processors on my dual Xeon servers, without any tweaks. I think it's pretty nice -- I'd say there's between a 5% and 25% pickup in performance, depending on what you're using it for (generic vs. optimized integer code).
According to a geek.com article, Linux was actually the first operating system to officially support hyperthreading, and that was in late 2001.