Is my HD 7850 underclocked?

[kLN93]

Hi, i've recently been having some problems with my new HD 7850, I get a fuzzy screen when gaming when I have Vsync turned off. When Vsync is turned on, it goes back to normal. I thought buying a VGA to DVI cable would fix the problem but it didn't. Could it possibly be caused by my PSU? I have a very old PSU, the max Watts is 300. But on the 7850 box, it says minimum required is 500w. I went into CCC and realized the GPU clock was set to 300MHz, even when running a game. The memory clock is set to 150Mhz, but the stock speed is 1200MHz, could this possibly be caused by my weak PSU?

Thanks

 

[Boozad]

Vsync will limit the amount of FPS sent your monitor to 60, so if you have a 60Hz monitor and Vsync turned off it could be your monitor failing to handle the output from the GPU. I'd leave Vsync turned on for a while and see if the problem reoccurs, but that's what it sounds like to me. What games are you playing out of interest?

 

[kLN93]

Vsync will limit the amount of FPS sent your monitor to 60, so if you have a 60Hz monitor and Vsync turned off it could be your monitor failing to handle the output from the GPU. I'd leave Vsync turned on for a while and see if the problem reoccurs, but that's what it sounds like to me. What games are you playing out of interest?

I have a old 60hz monitor with max resolution 1680 by 1050, when I turn Vsync off, the problem goes away completely. I'm going to try borrowing a friends monitor and see if it works on that one. Far Cry 3, Skyrim and Walking dead.

 

[Boozad]

I get a fuzzy screen when gaming when I have Vsync turned off. When Vsync is turned on, it goes back to normal.

when I turn Vsync off, the problem goes away completely.

Does the problem occur when Vsync is on or off? Those two posts contradict each other. I'd say the problem is with the monitor.

 

[kLN93]

I get a fuzzy screen when gaming when I have Vsync turned off. When Vsync is turned on, it goes back to normal.

when I turn Vsync off, the problem goes away completely.

Does the problem occur when Vsync is on or off? Those two posts contradict each other. I'd say the problem is with the monitor.

The problem only occurs when Vsync is turned OFF

Edit: I tried connecting my PC to a HD TV, but the problem still occurs.

 

[kLN93]

~bump

 

[stormy13]

Start with the PSU. From the sounds of it the PSU isn't strong enough and the card isn't getting enough power and staying in its low power state.

That and you're playing with fire running that system on an underpowered PSU, as if/when it goes it will likely take other things with it.

 

[Solarstarshines]

I think anytime you have V-sync off you are more acceptable to ripping and tearing and vert-lines because you are stressing the gpu as well when my v-sync isn't on my screen rips and tears because of cross fire it is extra bad

By keeping V-sync on it will keep the gpu temp down and keep the bad picture better and to the contrary stormy is also right usually that kind of card would be a 550w minimum you are under expectations

Ok Op seriously 400w PSU you are lucky to even boot :shock:
You need to get a better Psu or your going to make your rig a toaster

 

[Faladu]

Yeah OP, PSU up to 550W and you will have some headroom, 300W or 400W is asking for it with a gaming rig, not all PSUs are the same either, overdose your eyeballs at jonnyguru.com for a bit, a ton of PSU reviews/info there, he even takes them apart, DO NOT do that.

V-Sync is a good thing.

Of course if your video card can't handle the V-sync then the game performance is going to suffer.

 

[kLN93]

Thanks for the tips guys, i've just ordered a 600w PSU