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GPU at PCIE 2.0 x16 Slot running at x4!

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llort14

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Mar 26, 2012
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Hi guys, I've come to see if you can help me a little bit with this problem that has me tired of looking for a solution.
I just bought a Asrock M3A790GXH/128M Motherboard, and everything is working fine, except for my GPU.
Right now, I have a Nvidia GTS 250 1gb ddr3, and this GPU is inserted in the x16 green port, and everything is physically correctly, yet, by some reason, GPU-Z and AIDA64 report is running at x4.
I've tried updating BIOS, cleaning the GPU and slot, reinstalling windows and drivers, clearing CMOS, checking for an option in BIOS and I'm being unable to solve this issue.

Could anybody please help me with this?

Thanks in advance
 
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if it is a "bug" then it sounds like a whacky sensor. some cpus can have a sensor that "sticks" at 32c even if the temp is lower but they are fine. if it is a "problem" anything would be a guess without diagnosing what the problem is.

i do not know if you talked to asrock or where you bought the board from about the situation. you might want to let them know what happened (the reading apparently being off), what you have done (researched and tested), and ask if they think you should be concerned about it.

it sounds like your willing to live with it. but if something does go wrong, you're stuck. by contacting a tech support atleast you may be able to recover the loss of the board if it gets that bad.
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It could be that while the GTS 250 is mechanically x16, it is electrically x4, which is not unheard of.

Your board has 3 x PCI Express 2.0 x16 slots (green @ x16 mode, blue @ x8 mode, orange @ x4 mode) as a footnote.
 
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First of all, thanks for replying.
Maybe you're right since I see that performance is the same like this that when the GPU was at a PCI-E 1.0 x16 slot.
Also, could it be possible that it's a bad reading?
A friend told me that some motherboards send a bad report of the speed of the PCI-E Bus, although it may be working at x16.

And yes, like I said, the GPU is at the green slot.
What would mean if the GTS 250 is electrically x4?

Thanks!
 
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Thanks for replying.
Well, I already stressed and checked the options for PCI Express energy saving (off) and nope, the GPU still keeps at @x4.
To be more precise, AIDA64 and GPU-Z reported PCI-E 2.0 X16 @X4 even when stressing the GPU.
 
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well i have never heard of a card configured @ x4 but i can't say it isn't so. since the GTS 250 is not a high end card it is not being hampered by that configuration. would be nice if you had another card to test.

EDIT: actually that card SHOULD be x16 . . try it in the x8 slot.
 
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I haven't tried at the x8 Slot, but I did a little test.
This motherboard has a switch to change from 1 single GPU x16 to x8 in the green and blue slots in order to use Crossfire.
I did that, tested at the green slot and PCI-E was x4 still.
I'm going to try with the Blue x8 Slot.
 
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Mmm maybe you are right.
I forgot to mention that first, the GPU showed at x2!
Then, I cleaned the contacts using an erased and isopropyl alcohol and it went to x4.
I tried reseating it like 4 times, cleaning the contacts and also blowed the PCI Express Slot.
Maybe the slot has dust or something similar. Do you know how to clean it? Just to try as well that.

Thanks!
 
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Any dry cleaner used to clean the DVD lens or the Blu-ray drive should be okay, first blow up the PCIE slot from dust, then spray it too much with the dry cleaner. then blow up again and insert the PCIE card after you clean it too.

Make sure it's full seated, no golden pins are shown up.
 
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Ok, I'll do that as well.
Just a little question, do you think that it has something to do with the fact that after cleaning it a bit, the bus went from x2 to x4?
Maybe like you say, all it needs is a deep clean.
 
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i am smacking myself with a 2x4 for overlooking the simplest solution that ilysaml brought up.
yeah is sounds like a cleaning is needed and ilysaml is being a great help with that :)
 
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Thanks for explaining me how to clean it.
Right now I don't have any dry cleaner to spray or compressed air (I'll buy tomorrow), so I only have isopropyl alcohol, brushes, and microfiber cloth.
How can I try to clean them by using these items I have right now?

Thanks, you've helped me so far!
 
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i know you are anxious to fix/clean out the slot and you can do with with a microfiber cloth that is dampened with the alcohol. but it is best to follow it up by blowing it out with a compressed air to help dry it, though the alcohol does dry fast, and to get any little pieces of junk the cloth can't get.
 
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Mmm yeah you're completely right.
I'll wait til tomorrow to buy a can of compressed air and a dry cleaner, and I'll let you know if that solved this odd issue.

Thanks!
 
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Just a PCI USB 2.0 Card, on of these that allow you to have 4 extra USB slots.
Well, I tried by removing this card and no changes were made, but I haven't tried moving it to another PCI.

Also, a friend was telling me that some Asrock motherboards have a problem not showing actual speed, since he told he had the same "issue" and tested with a lot of GPUS and compared FPS in games in other Motherboard that showed "x16" and FPS were the same, with cards like Nvidia GTX 285.
Could this be possible? I've noticed that the FPS in Skyrim for example are about the same that in my old motherboard that used to be PCIE 1.1 x16.

Thanks for replying! 😛
 
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I haven't fully tested the performance in games, just with Skyrim.
Just of curiosity, a GPU like the GTS 250 would be bottlenecked if it were really at PCI Express 2.0 x4? I read somewhere else that it may decrease performance up to 15%
 
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Yeah, I don't believe a GTS 250 would have a big lost in performance.
But could it be possible what I mentioned about showing wrong readings?
Readings were taken using AIDA64 and GPU-Z and both showed the same speed.
I read in other threads that there are some more reliable ways to obtain the actual speed of the PCIE.

In the Info. of system in Nvidia Control Panel, it just says "PCI-E Gen 2.0 X16"

Thanks!
 
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Ok I just cleaned the PCI Express Slot and the contacts of the GPU again, following the process from ilysaml and no changes ocurred, GPU still running at @x4!
What else could be the cause of this odd issue?
 
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Ok everybody, first of all thanks for all of your replies, I hope this will be helpful to other persons with similar issues.
After reading a lot of things through Google, I found that some motherboards have a bug when reporting real PCI Bus.
I read that the best solution would be to check the actual conection bus by using HWINFO and this one reports GPU running at x4 like always but with a conexion bus of 5gb/s.
Is this the actual speed of a PCI E 2.0 x16?

Thanks!
 
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your board has PCI-E 2.0 that is 500Mbs a lane. so a x16 ought to be 8Gbs.
so your x10 now? 😛 ( does not compute . .)

i'll tell ya what. play an older game, one where that card has been benchmarked at like far cry2 if you have it. if the fps is close to the same, ignore everything.
 
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