Shocked by the low performance of a Q9550...

OK, a real shocking thing just happened. I have just removed the GT 730 1GB GDDR3 GPU and used the integrated MoBo GPU Intel GMA 3000. Suddenly, the videos in YouTube, that started to sound pop and lag if set to 720p or more, played back great. I'm speechless. I've checked the GT 730 in another PC and it's working great, benchmarked it and it scores what it's supposed to. So no, it's not a defective GPU.

Could it be that the PCIe x16 was version 1.0 and the GPU was bottlenecked by that, so it couldn't deliver it's full power?

I actually don't know what happens when you plug a PCIe 2.0 GPU into a PCIe 1.0 slot. My guess is that it will work worse, or even have some performance issues, such as what I was experiencing: audio popping, videos lagging that the CPU can handle perfectly...

The GPU couldn't fit directly to the case, it was not plugged directly to the PCIe x16 slot of the MoBo, but to an adapter plugged to that MoBo. I say this because it could be that the MoBo PCIe x16 was 2.0 but the adapter was 1.0. I've tried to find that info but can't, the DELL manual doesn't mention the version of the PCIe, and some users in Dell forums say it's 2.0 (if you update the BIOS???) and others 1.0.

rambomhtri said:

The GPU couldn't fit directly to the case, it was not plugged directly to the PCIe x16 slot of the MoBo, but to an adapter plugged to that MoBo. I say this because it could be that the MoBo PCIe x16 was 2.0 but the adapter was 1.0.

Can you explain why you can't attach the GPU card directly to the PCIe slot?

Megahertz said:

Can you explain why you can't attach the GPU card directly to the PCIe slot?

Ztruker said:

I think the is the motherboard, and the PCI-e slot looks clear and easily accessible:

That is like the less important point/thing I just said. It just didn't fit, a bunch of capacitors were too high to let the GPU correctly go down all the way. Low profile, by the way. I had to use the original Dell weird gigantic piece that turned 90 degrees the PCIe, and then the GPU would fit.

Anyways, that's not what I'm interested in, I was asking if all of this could be that it was connected to a PCIe x16 1.0 instead 2.0.

If the original Dell manual for the Optiplex 755 doesn't mention the PCIe revision, how can I know it?

Try to find it out, I can only find users in the Dell forum that say it's this or that revision without any proof. It's also not written on the board.

The adapter is this one:

DELL Riser PCI-PCIe FOR OptiPlex Desktop GX620 740 745 755 760 780 G5459 HX727 | eBay

Hi,
Not all that odd performance wise
Laptop has twice as fast memory than the desktop shown by performance test 9 results.
Yes system memory matters

Try to use passive PCIe x16 riser cable. Check GPU & audiochip drivers. For testing, leave the case open & put GPU directly into black slot (remove GPU bracket if necessary).

Q9550 + GT730 should play 1080p+ without problems.

My God, I didn't know I didn't put that info. It's the SFF, not the ultra slim one. Sorry for that, editing first post...

- - - Updated - - -

OK... so I took the GT 730, put it inside a newer PC, and tested its performance. Then I compared those with the test I did when I had the 755 with the adapter and everything. In the newer PC the GPU performs way better.

So, is this a proof the connection between the GPU and the MoBo somehow was problem and was causing all the audio pops, even in games from 2005, all the audio lags, clicks?

The 755 SFF is already "out", I removed some components and stored it in the attic. The GT 730 wouldn't fit, with or without the case top, because capacitors soldered to the MoBo wouldn't let it go all the way down. There was no way to test it without using the adapter.

Same GT 730 1GB GDDR3 64 bit (GK208-301-A1) 23W, top raw Dell 755, bottom HP 8200: