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144Hz Fluctuating GPU clock speeds

CF User

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Joined
Jul 31, 2015
Messages
6
Hey there, I'm having this strange problem with my new configuration, which includes a 144Hz monitor.
The clock speed of both GPU's are fluctuating in pretty much every 3D application. It can range anywhere from 750MHz - 1000MHz but only in 120Hz or 144Hz mode.
In 60Hz mode the clocks are rock solid @ 1000MHz... I'm not sure if 3D and 2D clocks are conflicting or whatever but any help would be much appreciated :thumb:

P.s temps are fine



Cheers

Setup:
I7 3770K @ Stock clocks / undervolted stable
Asus P8Z77 V LX MOBO
Corsair vengeance 16GB 1600MHz RAM
H80i closed loop water cooling for the CPU
2 x Sapphire R9 290's Tri-X
1TB Samsung HDD
250GB Samsung EVO SSD
RM1000 PSU
 

SKYMTL

HardwareCanuck Review Editor
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Feb 26, 2007
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Montreal
Do you have V-SYNC turned on? Alternately, the new AMD drivers introduced Framerate Target Control which has been known to enable itself randomly after a reboot. Check whether or not that turned itself on.
 

Lysrin

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Mar 10, 2014
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...the new AMD drivers introduced Framerate Target Control which has been known to enable itself randomly after a reboot. Check whether or not that turned itself on.
That seems like a helpful feature! :doh: Egads...
 

CF User

Member
Joined
Jul 31, 2015
Messages
6
Vsync + Frame target

Do you have V-SYNC turned on? Alternately, the new AMD drivers introduced Framerate Target Control which has been known to enable itself randomly after a reboot. Check whether or not that turned itself on.
V-Sync is off, both on 60Hz and 144Hz. Checked and frame rate target is off.

Also I just ran 3DMark and found that GPU-Z introduces infrequent stuttering (not a large amount but noticeable every 5-6 seconds.) Is it possible that my monitoring software is to blame? Used MSI before that though and it showed similar results. Ahh I just don't know :sad:

P.s GPU-Z is reporting that my second R9 290 is running 'PCI-E 3.0x16 @ x4' Shouldn't both cards be running @ 8x?
 
Last edited:

SKYMTL

HardwareCanuck Review Editor
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Ah. I just noticed. Your motherboard is only rated to a max electrical speed of x4 for the second PCI-E slot. Your cards are being bottlenecked by your mobo. Since one can't process data through the PCI-E bus fast enough (it is only working at x4 speeds) Crossfire fluctuates the clock speeds to compensate.
 

CF User

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Jul 31, 2015
Messages
6
Ah. I just noticed. Your motherboard is only rated to a max electrical speed of x4 for the second PCI-E slot. Your cards are being bottlenecked by your mobo. Since one can't process data through the PCI-E bus fast enough (it is only working at x4 speeds) Crossfire fluctuates the clock speeds to compensate.
:doh:Of course! Bit of a bummer, but in a way I'm glad the problem has been routed. Tried pretty much everything I could think of in the process.

Thanks very much for your help! :clap:

(Might have to run like this for a while until my budget allows otherwise) :bananafunky:
 

SKYMTL

HardwareCanuck Review Editor
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Where do you live? I MAY have an extra Z77 motherboard I no longer need for testing. If you live in Canada, I'd be more than happy to test it out to validate its working condition and send to you provided you pay for shipping. :)
 

Lysrin

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... If you live in Canada, I'd be more than happy to test it out to validate its working condition and send to you provided you pay for shipping. :)
See that? This is just another example of why this community is absolutely brilliant!! :clap:
 

SKYMTL

HardwareCanuck Review Editor
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Joined
Feb 26, 2007
Messages
13,410
Location
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I'll be putting up a Garage Sale thread in a few days with stuff I just have lying around. Figured I may as well start cleaning house now. ;)
 

CF User

Member
Joined
Jul 31, 2015
Messages
6
Where do you live? I MAY have an extra Z77 motherboard I no longer need for testing. If you live in Canada, I'd be more than happy to test it out to validate its working condition and send to you provided you pay for shipping. :)
:shok: Wow, really? Nice one. Cheers for the offer, but I live in the UK. Not sure how much it would be to send but I could cover the costs if it wouldn't be too much trouble? (Also not sure if it would be diminishing returns/ postage is through the roof.) Never the less, a generous offer :thumb:

If interested message me
 
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