Intel 925X and Socket 775 Platform: PCIe and DDR2

PCI Express – Performance

With all the controversy over the need for PCI Express, at this time in the technology’s life, I decided to try and show you if there were any performance gains using currently available software, to having a PCI Express motherboard and graphics card. 

That turned out to be quite the difficult task to do. 

The problem is that articles like this one (http://www.sudhian.com/showdocs.cfm?aid=554 ) are fundamentally correct — not many (if any) current day applications for the end user require the bandwidth that x16 PCIe is going to offer.  What will?  I already mentioned HDTV editing and rendering, but even this is only in extreme cases.  Intel cites an experience with rendering 4 720p image streams (HDTV) as quickly as possible, gives them up to 2x the frame rate over AGP 8x.  I’ve never done that, or needed to, and I can’t think of anyone that has. 

So, where did that leave us?

I looked to the synthetic tests in 3DMark03 for an answer, taking note of the fill rate tests in particular.  If anything might show an advantage for current generation graphics cards, then increasing the fill rate should be one of them. 

System Setup

• Intel 3.4 GHz 478-pin w/ 875 Motherboard
• Intel 3.4 GHz 775-pin w/ 925 Motherboard
• NVIDIA GeForce 6800 GT
• AGP on 478-pin
• PCI Express  on 775-pin

As you can see, the differences that we see here are almost negligible.  Besides that fact, we have to consider that these two tests (as with all of our comparative benchmarks) are run on completely different platforms, and thus bring about some difficulty in direct comparison.