Help, Sapphire rx 480 works at pcie 3.0 x4 instead of x16

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
Hey, I recently bought a Sapphire nitro+ rx 480 8gb oc. I have a gigabyte z77-ds3h mobo, i5 3570k pcu (not oced) and thermaltake litepower 600w psu : http://www.thermaltake.com/products-model.aspx?id=C_00001775

I have struggled for a few days to make the gpu work at the topmost pcie 3 x16 slot. It was working in the bottom slot which is pcie 2.0 x4 but not in the pcie 3.0 one.

After clearing cmos, updating bios and fiddling with the bios settings I have managed to make it work with the pcie 3.0 slot but now it is only wowking at x4. It stays at pcie 1.1 x4 when idle, and switches to 3.0 x4 when under load but couldn't manage to rise it higher. Also I am pretty sure gpu is well fit in the slot.

After a restart yesterday, my gpu started to work at pcie 3.0 x16. However after a few seconds of load it stopped working alltogether. It continued with all kinds of problems like not being recognised at the start, crushing windows, bsods etc, until I switched pci slot back to 2.0 and then to 3.0 again. It is working at 3.0 x4 fine again. Guess I will need to replace my mobo or psu but I don't know which causes the problem. But I am more and more worried about my psu as it has 12v dual rail with 25 and 20 amps respectively.

I am also willing to leave it like that but I am not sure about a potential bottleneck.

And rma conditions are pretty terrible in my country so I prefer solving it inhouse if that is possible.

Sorry for the long post, any help is greatly appreciated:)

 

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
I was on the latest drivers. I have bought an ssd with the gpu and made a clean windows install along with the gpu installation on which only amd drivers are installed.
 

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
Here is the dxdiag output : https://paste.ee/p/mbO9D

I don't have any other card.

I have resetted the cmos and updated the bios to latest beta version, which mentions fixing pcie 3.0 compatibility issues. Only then, I managed to make the card work with the topmost pcie 3.0 slot.
 

Lutfij

Titan
Moderator
For some odd reason Gigabyte's site isn't working for me. Drop down from your beta version of BIOS to the latest non-Beta version. Beta's aren't reliable and in fact if anything it's only a small poke at the end user since Intel is now in the 7th Gen of it's processor range meaning that motherboard manufacturers would more likely focus their support to later and upcoming hardware's support.

What OS were you on prior t migrating to Windows 10?
 

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
Well I am using 10 for a very long time. I was using windows 10 on another hdd with my old gpu. When I installed the gpu, I installed an ssd with it and made a fresh install. I was using windows 8.1 before that.
 

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
Alright, might give that a try, thanks for advice.

And btw, even if that problem isn't because of the psu, should I still change it to prevent future disasters? I know my card is very demanding about psu and I also know that my psu is not top tier however 600 watt total and 25+20 amps on 12 v rail seems plenty to me.

If the answer is yes, what would be an ideal psu or what should I look for?
 

Lutfij

Titan
Moderator
Definitely buying a reliable PSU is one of the first things you should do. The PSU is considered to be the heart of the system so if it were to have a heart attack, it'll take everything that is connected to. Often the PSU's wattage and the rails/amperage can be falsified to fool the uninformed customer.

What sort of a budget are we looking at and where are you located?
 

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
I'm in Turkey and don't have access to many of the premium psus. About budget, I am considering 100$ max. The only good psu I managed to find was Seasonic s12ii 620w but it is dual rail too I guess. Other than that, there are some zalman psus, corsair vs series and more thermaltake litepower, toughpower and smartpower.
 

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
Hmm I really don't understand psus:D Since both seasonic and my psu are dual rails and amp outputs are nearly identical, is it the build quality that makes seasonic superior? Oh also found some corsair cx and cxm psus however they are a bit expensive.
 

EvrimKaya

Commendable
Feb 2, 2017
13
0
1,510
UPDATE : So I replaced my psu with a Seasonic S12II. The problem still persists but at least I am not worried about frying my gpu:) I tried the gpu on another machine and it works at 3.0 x16 without any problems there. So I think my mobo is the problem however I am not really willing to replace it for the moment. I am planning to use the gpu at the lower pcie to prevent any damage from the broken slot even when the top slot works 2x the speed. (ps: it works fine at 3.0 x4 at the top slot however sometimes at restart it switches to x16 and crashes a few times until it reverts back to x4 by itself)

I haven't noticed any performance issues using pcie 2.0 x4, I hope I am not terribly wrong about that.