Will a GTX 780 work with a Q8400?

#1 Edited by Burnchild_Ren (97 posts) -

I finally have the budget to buy a card that will be capable of keeping my rig in the game for a while longer.

It seems that the card that best suits my interests in terms of budget and performance is the GTX 780, which would be replacing my HD 6850.

However, I'm still running an old Q8400, which is slightly weaker than an i5, perhaps on par with an i5 if overclocked properly. While I won't pretend to understand CPU-GPU relations, what I do know is that having a really old CPU and a really new GPU may cause the GPU's performance to be hampered.

The question is, will my Q8400 bottleneck a GTX 780 if I were to install one? If it will, what's the cheapest CPU that won't bottleneck it?

On a slightly different note - if I install a GTX 780 and it does end up being bottlenecked by my Q8400, would it still be able to handle Watch Dogs on higher settings?

#2 Posted by GTR12 (10016 posts) -

The 6850 was being bottlenecked by the Q8400...

#3 Posted by Burnchild_Ren (97 posts) -

@GTR12 said:

The 6850 was being bottlenecked by the Q8400...

I strongly doubt it. Judging by several monitoring programs, it seems that my 6850 is performing according to it's specifications.

#4 Posted by GTR12 (10016 posts) -


Check your 3D mark score against similar rigs except with better CPU's.

#5 Edited by Coseniath (1260 posts) -
@GTR12 said:


Check your 3D mark score against similar rigs except with better CPU's.

I strongly disagree too. Even a GT520 would score different between a Q6600 and an i7 4790K.

3Dmark has a different way of benchmarking things. Especially in 1280x720 Firestrike which cause of the low res is more CPU depended than a game at 1080p.

But generally a Q8400 would not bottleneck an HD6850.

GTX780 on the other hand is an other story.

Your Q8400 will surely bottleneck a GTX780. But that doesn't mean that you will not see improvement from a 6850.

But a GTX780 costs $450-500. I would use $250-300 for a CPU/Mobo upgrade and keep the rest of the money for this:

NVIDIA Timing GeForce GTX 880 Launch with Gamescom?

#6 Edited by Grey_Eyed_Elf (4076 posts) -

My Phenom II X4 bottlenecked my HD 6950... So I would assume that in CPU intensive games that yes a Q8400 would be a substantial bottleneck especially if its not overclocked.

CPU bottlenecking is genuinly a issue if you have a high end GPU and a CPU that is weaker than a i5 in a lot of games... In some games it doesn't matter, if you look at the BF4 singleplayer benchmark you will see that the difference between the FX 4100 and a i7 is almost nothing, but then you look at other games and the difference is almost twice the framerate. If your Q8400 isn't overclocked you are potentially bottlenecking the GTX 780 by 30-40% of its performance.

#7 Edited by 04dcarraher (20342 posts) -

Cpu bottenecking is dependent on the software's cpu and gpu needs. While the TC's E8400 wont bottleneck that 6850 normally unless the game requires more processing power then it can provide. Now with a GTX 780 o yes a E8400 would definitely will hold back the gpu. Unless your only running games that are only wanting a dual core or even one core with processing power that wouldn't stress that cpu to the brink. But even still going from a 6850 to a GTX 780 would see massive gains but not as much as you would by going with a new cpu with a GTX 760.

an i5 4670k z97 board and 8gb of ram and a GTX 760 for around $650 would give a almost a brand new machine that would run circles around a system with an e8400 and gtx 780