7950 at PCI 2.0 8x

[Caat]

I am in the process of slowly upgrading my decrepit desktop PC. It's evolved through the years and currently consists of:

QX6700 @3.2, 4Gb RAM, 256Gb C4 SSD, AMD 7950 3Gb

I picked up the 7950 a couple of days ago from a reputable online retailer for a total steal price 2nd hand -> £33!!!! So naturally I got even though I knew the CPU is the bottle neck. I've been intending to upgrade my primary HDD to an SSD for ages. So I did that at the same time

I have an ASUS PCI-E card that adds USB 3.0 and two sata III ports. The SSD is measureably quicker when attached to it rather than a motherboard sata II port but it means that the second PCI-E slot takes bandwith away from the graphics card.

So with the SSD on sata III the 7950 is on PCI-E 2.0 8x. Without it the 7950 gets the full 16x - my motherboard is odd in having two PCI-E slots but only the bandwith for 8x and 4x or 16x and nothing.

My question is therefore: will I get better noticeably gaming performance with the 7950 at 16 x rather than 8 x?

Thanks!!

nb that in the next month or so I will probably be going Ivy Bridge.

 

[The_Golden_Man]

I am in the process of slowly upgrading my decrepit desktop PC. It's evolved through the years and currently consists of:

QX6700 @3.2, 4Gb RAM, 256Gb C4 SSD, AMD 7950 3Gb

I picked up the 7950 a couple of days ago from a reputable online retailer for a total steal price 2nd hand -> £33!!!! So naturally I got even though I knew the CPU is the bottle neck. I've been intending to upgrade my primary HDD to an SSD for ages. So I did that at the same time

I have an ASUS PCI-E card that adds USB 3.0 and two sata III ports. The SSD is measureably quicker when attached to it but it means that the second PCI-E slot takes bandwith away from the graphics card.

So with the SSD on sata III the 7950 is on PCI-E 2.0 8x. Without it the 7950 gets the full 16x - my motherboard is odd in have two PCI-E slots but only the bandwith for 8x and 4x or 16x and nothing.

My question is therefore: will I get better noticeably gaming performance with the 7950 at 16 x rather than 8 x?

Thanks!!

nb that in the next month or so I will probably be going Ivy Bridge.

No, the difference would almost be zero on a single 7950. You're biggest bottleneck is your current CPU. Ivy will fix that though.

 

[TakeNoPrisoners]

That CPU isn't really a bottleneck, especially if you overclock it a bit; that GPU won't be bottlenecked by pci-e 2.0 8x.

 

[The_Golden_Man]

That CPU isn't really a bottleneck, especially if you overclock it a bit; that GPU won't be bottlenecked by pci-e 2.0 8x.

Oh, yes that CPU will be a bottleneck. Min FPS will suffer in games. Even my Q9650@4GHz began to show bottleneck for a GTX 570 and was much worse with a GTX 670.

 

[Protomize]

Oh, yes that CPU will be a bottleneck. Min FPS will suffer in games. Even my Q9650@4GHz began to show bottleneck for a GTX 570 and was much worse with a GTX 670.

Average FPS is all that matters and that CPU won't be a bottleneck according to that.

 

[The_Golden_Man]

Average FPS is all that matters and that CPU won't be a bottleneck according to that.

You're wrong. Min FPS is the most important. Since that is what can ruin the gaming experience. A weak CPU in combination with a newer tech/fast card will make the system very unbalanced. This can cause the min FPS to dip very low in many recent games.

Often times these min FPS do not show up in benchmarks, but are experienced in gaming.

 

[ShintaiDK]

Agree, min FPS is alpha omega. Having a min FPS of 15 makes a game disasterous. Even tho it runs 120fps most of the time. The 30fps min, 60fps average would easily beat it.

 

[lehtv]

Agreed, average framerate is only part of the answer. In scientific publications, an average is almost always accompanied by a standard deviation, too bad that's not the case in hardware reviews

 

[TakeNoPrisoners]

Oh, yes that CPU will be a bottleneck. Min FPS will suffer in games. Even my Q9650@4GHz began to show bottleneck for a GTX 570 and was much worse with a GTX 670.

I'm not sure what you mean by "show a bottleneck". If the CPU was bottlenecking performance then the minimum FPS will be the same with both the 570 and 670.

CPU bottlenecks can also show up in max fps readings too, it all depends on what the game stresses most.

Either way, I would be comfortable running a 7950 on that processor, however I would want to put an overclock on it.

 

[lehtv]

The GTX 570 wouldn't be bottlenecked all the time, so despite the same minimum fps, the bottleneck would manifest more easily with a faster graphics card. It'd limit the increase in average fps.

 

[toyota]

Average FPS is all that matters and that CPU won't be a bottleneck according to that.

 

[Caat]

Thanks guys!

I'll stick to using the ASUS add in card then.

One thing I will say is that Skyrim looks a lot better with an AMD 7950 than an AMD 5770 regardless of processor!