Xeon X3470 and PCI Express lanes limitation

JamesKIWI

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Jan 11, 2016
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I recently purchased a used Xeon X3470 to replace my Core i5-760. I wanted to upgrade to the i7 and since the X3470 is pretty well identical to the i7-870 but cheaper I thought it was a better buy.

All the forums I read did not mention any major difference except for the memory ECC support on the Xeon and my motherboard listed it as a supported CPU. So I decided to buy it. The X3480/i7-880 is only ~3% faster compared to the X3470/i7-870 so not worth the premium in price for my budget.

However when doing a side by side product comparison I spotted a difference that concerns me.
The Xeon CPUs have a maximum # of PCI Express Lanes of 1 while the i7 equivalents have a maximum # of PCI Express Lanes of 16.

Does this mean that the graphics performance with a PCIe graphics card and Xeon CPUs will be inferior to the equivalent i7?

What exactly does this difference of maximum # of PCI Express Lanes imply?

Thanks for taking the time to respond.
 


Thanks, I hope that's the case. I found the information on the Intel site here: http://ark.intel.com/compare/41315,48496,42932

But cannot find the same spec specified in other sites like CPUBoss.com or CPUupgrade.com

I posted the question on the Intel Forum and just received this answer from Intel (13/01/2016):
"The Intel® core i7-870 and the Intel® Xeon® Processor X3470 support x16 graphics cards. The difference here is that the Xeon processor will send the information using one lane and the i7 processor will use 16 lanes so it will have better bandwidth."

So I believe there is a difference and the Xeon counterparts to the i7 should perform worse for graphics.

Which is still puzzling because the limited benchmarks on the X3470 I have seen do not show a significant difference.

Anyone else have a comment?





 
Have you tried any benchmarks to try and test the PCIe speed? I have to agree this seems to be a typo or data error to me. I was looking in to this while researching the X3440 which has the same thing and came across this thread and the thread on the Intel forums but so far, haven't found good confirmation (e.g. someone saying it's definitely wrong or the it has 16 lanes). The strongest confirmation I have thus far is the Intel data sheet http://www.intel.com/Assets/PDF/datasheet/322371.pdf seems to strongly imply it has 16 lanes if I'm understanding it correctly.