Any point in using high end card with 1'1?

[cryingrobot]

First of all thanks to tiamo for breathing new life into the old warhorse. I have the 1,1 running mavericks and even installed a Gtx660. While it is definitely faster than my 4870, it seems not as fast as it should be. My iMac with 775m seems smoother.

I have heard a few different things on the PCI bottleneck with some people saying it should not be a bottleneck yet but others have said there is really no benefit from running anything like a 660 on a 1,1 as performance will be bottle necked.

Any thoughts on this?

 

[slughead]

First of all thanks to tiamo for breathing new life into the old warhorse. I have the 1,1 running mavericks and even installed a Gtx660. While it is definitely faster than my 4870, it seems not as fast as it should be. My iMac with 775m seems smoother.

I have heard a few different things on the PCI bottleneck with some people saying it should not be a bottleneck yet but others have said there is really no benefit from running anything like a 660 on a 1,1 as performance will be bottle necked.

Any thoughts on this?

The PCIe bottleneck will bring the max throughput to PCIe 1.1 16x, which is the same as 8x PCIe 2.0, which is 4GBps.

According to this article, this will limit performance by 2-4% on the midrange (~$300-450) cards of today (7970/680 and probably 770).

Not bad.

You might have some slowness from the CPU, but you will definitely see a benefit of a 660 over an 8800GT or X1900... maybe even 5870/5700, but I would have to look it up.