PCI-e speeds discrepancies

[tobiftw]

Hey guys, I have some weird graphics card issues on my board right now.

Specs are:

• Optiplex 755 (Mid-tower) Motherboard(https://www.dell.com/downloads/global/products/optix/en/opti_755_techspecs.pdf)
• PNY GT 730 1GB GDDR5(https://pny.com/gt-730-1024mb-gddr5)
• Intel Q6600 Processor (http://ark.intel.com/products/29765/Intel-Core2-Quad-Processor-Q6600-8M-Cache-2_40-GHz-1066-MHz-FSB)\
• I've turned off all possible power-saving adjustments, both in the BIOS, and in the nvidia control center and windows power mangement.
• BIOS is pacthed to the latest version (A22)
• Nothing else is inside any other PCI-e slots
• If I'm missing anything else necessary to debug this, lmk.

So here's my issue: my graphics card is running (according to GPU-z and nvidia inspector) at x1 speeds with gen 1.1, while it reports that it can run at x8 v1.1 speeds. Doing the common stress test on both GPU-z and 3d-benchmark doesn't help, it still stays at x1 speeds. Re-seating or cleaning the card/slot doesn't help either. According to this post with the same motherboard and similar graphics card http://en.community.dell.com/support-forums/desktop/f/3515/t/19986614, it says that the Optiplex 755 MT's chipset and board doesn't recognize cards with x8 or x4 speeds and locks it at x1. This makes sense why it seems stuck at x1 speeds, since gpu-z and cpu-z say the max bandwidth my card reports is at x8.

 

But the off-thing is that according to PNY, it's supposed to run at x16 v2 speeds, which makes me suspect that either the motherboard is reading the card wrong, or the card is reporting wrong speeds back to the motherboard. How can I get my motherboard to recognize my graphics card's F U L L  P O T E N T I A L ?

Thanks!

[tobiftw]

bump

[Man]

I know this thread is ancient, irrelevant to most users of this forum and the OP is no longer active but the sole reason I'm reviving this is because a lot of budget gamers are facing similar issues with Optiplex 755 machines (Including yours truly) where the GPU is stuck at PCIe v1.1 x1 speed, no matter what. I'm here solely to help out people who are facing similar issues with the 755 machines. 

 

As it turns out, these business PCs aren't exactly made for GPUs and hardcore gaming in mind. The culprit here is the Intel Q35 Express chipset, or so it seems. From what I've gathered from various sources and a few days of research is that this chipset can only run Nvidia Quadro GPUs reliably. And it makes perfect sense when you look at the motherboard:

 

 

The PCIe slot is practically surrounded by capacitors, so there's no way to mount dual-slot GPUs! The biggest pain are the two giant caps at the front of the PCIe x16 slot which is Dell's way of saying: "Buy an Alienware^TM if you want a gaming PC, dagnabbit!". I was lucky my Nvidia GT440 (Mac Edition) with a tiny little heatsink was able to squeeze inside that tiny little space. Unluckily however, it's ALSO stuck at PCIe x1 speed at v1.1 despite supporting 16x PCIe v2.0 so... You know!

 

Dell, eh?

 

Took me AGES to figure it all out! At first, I was certain it was Nvidia deliberately crippling my old GPU with latest drivers. Almost bought an HD8740, actually!

 

O' Nvidia, will you ever forgive me?

 

Anyhow, that's all I've to say. Let's hope this little rant help out people in the future who are wondering why their games are running like garbage, even when they aren't supposed to.