Tom's Hardware > Forum > Motherboards & Memory > General Motherboard > CrossfireX

CrossfireX @ PCIE 2.0 X4 speed, Is this fast enough?

Forum Motherboards & Memory : General Motherboard - CrossfireX @ PCIE 2.0 X4 speed, Is this fast enough?

Tom's Hardware: Over 1.4 million members in 6 different countries available to answer all your high-tech questions. Sign up now! Its free!
Ask the community Add a reply
Word :    Username :           
 
rapsux321   06-12-2009 at 08:30:03 PM

Hi, looking at the ASUS M4A78 Plus AM3/AM2+/AM2 AMD 770 ATX AMD Motherboard, I noticed the when in Crossfire the 2 slots being used run at PCIE 2.0 X4. Normally these run at least at 8x, and on better boards at the standard 16x. Most of the time 16x is overkill correct? 8x is probably more than adequate in most scenarios, but 4x seems a little sketchy. Anyone have experience or data that would say crossfire @ 4X is not enough bandwidth for video cards? or what card model would the cutoff occur at? Thanks!

Add a reply
Sponsored Links
Register or log in to remove.
megamanx00   06-12-2009 at 09:03:47 PM
- 0 +

Even toms has some articles covering PCI-E bandwidth affecting cards. Generally 4x is pretty low and will give a performance drop for a single card. As for crossfire it's best to have the slots using the same number of lanes. Mixing lanes, like a 16x and a 4x, limits performance and sometimes can actually lead to lower performance than just using a single card. Anyway you may want to check out this article on legion hardware to compare different crossfire setups

http://www.legionhardware.com/document.php?id=761

Anyway for modern cards you really should use at least two 8x slots. Of course two 16x PCi-E 2.0 slots is ideal, but they really only have a significant advantage over two 8x slots when using something more powerful than a 4850. It is pronounced when using dual GPU cards for 4way crossfire like the 4850x2 and 4870x2

------------------------------ Playing X-Men Origins: Wolverine Athlon 64 X2 5000+ @3.24 Brisbane | GIGABYTE GA-MA790X-DS4 | 4GB Mushkin DDR2 1066 | Plextor 760A| 2x 3850 512M CF| WD 1TB Black| Fortron Blue Storm II 500W | APEVIA X-Dreamer Black | Win XP Pro & Vista Buisness 32bit
 Reply to megamanx00
Ask the community Add a reply
Tom's Hardware > Forum > Motherboards & Memory > General Motherboard > CrossfireX
Go to:

There are 1154 identified and unidentified users. To see the list of identified users, Click here.

Forum map
Bestofmedia Forum ©
2000-2009 Bestofmedia Group
Page generated in 0.351 seconds
Sponsored links
  • Ask the community now
  • Publish
Ad
Related Topics
See all relatives topics
They won a badge
Join us in greeting them