Pci-e x16 2.0 @ x8?

[corbinw]

I have a m4n75td mobo with a AMD Phenom II x4 3.2ghz processor, along with my EVGA GTX 285.

When I got Speccy to look at how hot it ran, I noticed that it was running at x8, so then I installed GPU-Z to double check to make sure it was right, which it was.

I'm not sure how to make it run at x16, any help please


Corbin

 

[jryan388]

Which slot did you put it in?

 

[corbinw]

Both slots are pci-e 2.0 x16. I tried both and it still came up as x8

 

[hunter315]

Do you have something else in the other PCI-E 16x slot? Your board supports running one of them at 16x mode, or both of them at 8x so if the other slot is empty go check in BIOS to make sure its not looking to run two cards and automatically splitting the lanes.

 

[corbinw]

The other PCI-E 2.0 x16 slot is empty, I tried looking in the bios but I couldn't find anything to adjust.

 

[corbinw]

I attempted to rise the PCIe frequency higher, I got up to 120 from 100 and still at x8. I heard from another forum that it might work.

I really don't want to replace any parts or go through an RMA.

If it's something stupid like a bios thing or something I could do in windows, please let me know

 

[techgeek]

If you have a look at this link:

http://dlcdnet.asus.com/pub/ASUS/mb/socketAM3/M4N75TD/ie5353_m4n75td_insert.pdf

It says that the slots work in X8 mode regardless of single or dual card configuration. Weird, I have never seen a motherboard like this before. It has 16 lanes, but it seems that 8 of them are hardwired to one slot and 8 to the other, it can't allocate all 16 lanes to one slot.

It says much the same thing in the manual I downloaded from ASUS.

I wouldn't worry about it too much as HardOCP just did an article showing that SLI and CrossFire are not handicapped by running X8/X8 versus X16/X16. If running X8 on two cards doesn't bottleneck performance, X8 on a single card shouldn't be an issue.

Heres that article:

http://hardocp.com/article/2010/08/16/sli_cfx_pcie_bandwidth_perf_x16x16_vs_x16x8

 

[corbinw]

Well that's dumb. Why bother telling me it runs at x16 then turn around and say it doesn't.
But apparently it "handles" pci-e x16 cards, but runs them at x8. So whatever.

Anyway, it's good to know that I wouldn't really notice any difference from x16 to x8.

I do play a lot of Bad Company 2, so I was hoping if I did get x16 that it would be a huge performance increase, but now that I know that I can't change it to x16, I'm glad there isn't much of a difference.


Thanks a bunch techgeek, now I don't have to worry about it anymore.

Corbin

 

[corbinw]

Best answer selected by corbinw.