Hypernon

So I realised that my HD 4850 wasn't performing as well as it should be so I loaded up GPU-Z to find the problem. It turns out that the Bus Interface was PCI-E x16 @ x1. Knowing possible fixes to this problem already, I opened up my case and cleaned out my PCI-E slot. I rebooted and ran GPU-Z again. This time it said PCI-E x16 @ x4. Figuring that it was solely a dust problem I cleaned my slot again, and this time GPU-Z gave me PCI-E x16 @ x8. No matter how many times I clean it it won't give me full x16 performance, and sometimes it's at x4, sometimes x8. Does anyone know how I can get my card to run at x16 like intended?

Here's some information about my setup (Info gathered with Everest Ultimate Addition and HWiNFO):

OS Partition 1: Windows Vista Home Premium 32Bit SP2
OS Partition 2: Windows 7 Ultimate RC(7100) 64Bit
(Problem exists on both OS)
CPU: AMD Athlon 64 5200+ X2 2.6GHz Dual-Core Processor
RAM: 3GB DDR2 333.3MHz Nanya Technology SDRAM
Motherboard Model: Acer F690GVM
Motherboard ID: 06/25/2007-RS690-SB600-6A669FK8C-00
Motherboard Chipset: ATI RS690(M) + SB600
Motherboard Slots: 1 PCI, 1 AGP, 3 PCI-X, 1 PCI-E x1
(PCI-E x1? I have my PCI-E 2.0 x16 video card in this slot. Mustn't this slot be x16 to even fit the HD4850?)
BIOS Name: Acer, Phoenix - AwardBIOS v6.00PG
BIOS Date: 06/25/07
PSU: Corsair HX620 620W Modular Power Supply
Video Card: Sapphire ATI Radeon HD 4850 512MB GDDR3 PCI-E 2.0 x16
Monitor: Acer X203W

Let me know if you need anymore information.

Solutions I have tried:
Disabling "PEG Force x1" - There is no "PEG Force x1" option in my BIOS to disable.
Set the NB Vcore to 1.45V or less - There is no option to edit the NB Vcore in my BIOS, NB Vcore isn't even mentioned anywhere in my BIOS.
Tweak the PCI-E Reference Clock lower or higher - There is no PCI-E Reference Clock option in my BIOS to edit.
Clean the PCI-E Slot - I have done this 3 times now. I've blown into and onto the slot and card, wiped with non-lint cloth, and even used a fan close up on the slot, card, and surrounding areas.
Revert to Default Settings in BIOS - Didn't fix the problem.

I would greatly appreciate any help with this problem as it is frustrating me and I can't seem to solve it by myself.

Do I need to clean the PCI-E Slot better? Do I need to change a setting somewhere? Do I need to buy a new video card or motherboard? I'd like to exhaust all other options before buying new hardware, however.

Hypernon

I think the answer is that x8 is the maximum the slot can run at because the motherboard is permanently set to run it at 8x. Can anyone confirm this? I don't want to buy a new motherboard if I don't have to.

Phædrus2401

My guess is that Acer decided to be cheap when making their motherboard and make a PCIe x16 slot that only runs at x8. If so there isn't much you can do about it, short of getting a new motherboard. Don't go running off to buy one just yet, though! First, we need to find out if your PCIe x16 slot is 1.0 or 2.0. If it's 1.0 then you probably will need to get a new mobo to get the full power of your graphics card, but if it's 2.0 then it's likely that running at x16 won't give you much more performance than x8. The 4850 is a high end card, but not ultra-high end. It can probably deliver full or near-full performance at x8 2.0. It would need the full x16 if it's 1.0, however.

I'm not sure if Everest or HWiNFO would say if it were 1.0 or 2.0. I'll leave it to the experts to figure out how to detect that. I will say, if you're unlucky enough to need a new motherboard, go for Asus or Gigabyte. The only Acer products I trust are monitors.

ebackhus

Some slots are 16x length but only 8x electrically. Honestly, you won't see a difference between 8x and 16x.

Hypernon

This slot is PCI-E 1.0, not 2.0. So what you guys are saying is that I should be buying a new motherboard with a PCI-E 2.0 x16 slot if I want the full performance from my HD 4850?

Phædrus2401

Well... You'll see some performance over x8 1.0. Not a ton. But it's up to you if you want to spend $100+ on a new motherboard or not.

ebackhus

My mobo is just PCI-E 1.0 but my 3780 works great in it. I even threw in a 4870 and it was awesome!

Phædrus2401

Ugh, my post got swallowed by the black hole at the center of the internet. Gah.


Okay, basically, you might currently be getting a *slight* bottleneck from only running at x8 1.0. You might not. Even if you are getting a bottleneck, easing it will only increase your performance by 10% at most. If you feel that's worth shelling out $100 for a decent motherboard, go ahead. I'd leave it be, myself, but it's up to you.

Hypernon

Ok thanks for all the help guys. I realise getting a new mobo just to alleviate this issue is kind of an expensive solution, but the new mobo will also be helpful when I want to upgrade my CPU and RAM in the future, so it will serve more than one purpose. I think the issue is solved now, unless anyone knows of some way I can get my 4850 running at x16 on this mobo.

ebackhus

Unless there's a 16x slot it won't happen. WHile the 4850 is no slouch it won't even fully utilize 16x bandwidth. I can see how getting a new board will open up new possibilities for upgrades but I feel it's best to work with what you have until there's a BIG reason to upgrade and the price is right. Just my $.02 USD.

Hypernon

You do bring up a valid point. I'll think about this more.