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Perplexing OC'ing situation! Radeon 7950 OC = Lower FPS

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mysticjbyrd

New Member
Joined
Jun 3, 2016
This is the situation,

I load up GTA V, I got a specific spot in the club, and I get 85 fps, rock solid. Great, okay!

I turn on afterburner, turn up the power limit by 10%, and my boost clock becomes more stable, usually staying at 925, and I get 88 FPS. I undo this, and it returns to 85 fps.

I turn up Core clock 100 Mhz, and I drop down to 65-70 fps. My core clock frequency is bouncing all over the place! So, undo that, and set it back to 925. Solid 85 again.

I turn up VRAM +100 MHz, and again 65-70 fps. I undo it, and again rock solid 85 again.

I try a mix of the three, and the outcome is always the same, a drop of about 20% fps.


So, I tested it in the Witcher 3, and it was the same outcome.


So, I thought, maybe the Radeon Crimson settings were screwing up Afterburner. So, I did the OCs in Crimson, same outcome!


What is going on here?!
 

Lochekey

Senior Pink Member
Joined
Sep 13, 2015
Sounds like an unstable overclock, try working up by 25mhz increments and see where the instability occurs.
 
OP
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mysticjbyrd

New Member
Joined
Jun 3, 2016
I would assume that as well, but just an increase of a 100 Mhz is unstable!? That seems a bit insane! I will give it a shot though, thx.

Do you think it might be this old ****ty PSU? I also have a xeon x5650 with a bclk of 185 running atm.
 

Lochekey

Senior Pink Member
Joined
Sep 13, 2015
Could be. Did you try increasing voltage at all and are your temperatures in check?
 
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mysticjbyrd

New Member
Joined
Jun 3, 2016
I haven't tried increasing voltages, because I wanted to take it kind of slow, as I am a complete amateur at OC'ing stuff. I have tinkered with PCs for 20 years, but OC'ing was never something I was particularly interested in, as I wanted to ensure my components lasted as long as possible.
 
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mysticjbyrd

New Member
Joined
Jun 3, 2016
I increased the Core clock by 25 MHz while in game, and it did the same thing.

I reduced it by 25, and it dropped the FPS down to about 81 fps.


The core clock jumps around like crazy when I change the memory speed too!


This PSU is like 6 years old. I have a multimeter, maybe I should test it?
 

Lochekey

Senior Pink Member
Joined
Sep 13, 2015
If you can list the full system specs that would help, I'll list mine as an example.

I5-4690k
Gigabyte Z97X SOC Force
2x4gb Tridentx 2400 ram
2x - XFX hd7970
EVGA G2 750w psu
Cpu and GPUs under water

- - - Updated - - -

Something does not seem right did you update any drivers recently?
 
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mysticjbyrd

New Member
Joined
Jun 3, 2016
If you can list the full system specs that would help, I'll list mine as an example.

I5-4690k
Gigabyte Z97X SOC Force
2x4gb Tridentx 2400 ram
2x - XFX hd7970
EVGA G2 750w psu
Cpu and GPUs under water

- - - Updated - - -

Something does not seem right did you update any drivers recently?

Xeon x5650 BCLK OC 185
MS-7591
12gb 1600 Mhz Memory, clocked at 8*185=1480. I don't think xmp is enabled, so I think it might be running effectively at 1333.
7950 Boost
Air cooled

I think I updated the GPU driver recently, but that's it.
 
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mysticjbyrd

New Member
Joined
Jun 3, 2016
I fixed it. Changing the speed at all was forcing boost voltages, I think, and it somehow made it unstable. I had a feeling that my boost speed hasn't been working correctly for awhile now. It was never stable at 925, it's been jumping up and down like crazy between 850 and 925. I thought it was **** drivers for a long time, and I didn't know they increased the voltage for boost.

I increased the power limit by 20%, decreased the boost voltage from 1.25, and it seems to be stable at 1.15v 1050 Core 1500 memory.

It's almost hard to believe it's nearly 20% faster at a lower voltage than the boost.


Max temp in Valley was 76, which seems a bit high, but I have seen it get to 75 before at stock. Do you think cleaning it, and adding new thermal paste would be worthwhile?
 

chrisjames61

Member
Joined
Jul 14, 2013
Location
Holed up in Branford, CT
I fixed it. Changing the speed at all was forcing boost voltages, I think, and it somehow made it unstable. I had a feeling that my boost speed hasn't been working correctly for awhile now. It was never stable at 925, it's been jumping up and down like crazy between 850 and 925. I thought it was **** drivers for a long time, and I didn't know they increased the voltage for boost.

I increased the power limit by 20%, decreased the boost voltage from 1.25, and it seems to be stable at 1.15v 1050 Core 1500 memory.

It's almost hard to believe it's nearly 20% faster at a lower voltage than the boost.


Max temp in Valley was 76, which seems a bit high, but I have seen it get to 75 before at stock. Do you think cleaning it, and adding new thermal paste would be worthwhile?

Whenever I buy a used gpu I completely disassemble it, clean it and reapply the tim. If it has pads I apply tim instead instead of using the pads.