Thinking about crossfiring 2x 4870 512's

[Pigbearman]

Well, I made this computer about three months ago. So far everything is running perfectly. I'm thinking about upgrading it a bit by adding a new videocard and another 1TB hard drive.

First off:

1. My motherboard (Gigabyte EP45-UD3P) has two PCI E 2.0 slots, but if I were to crossfire, they would only be running x8 x8. Is there any real disadvantage to having the cards run x8 x8? Will I still see an increase in performance?

Also

2. My CPU is only a C2Duo E7400 OCd to 3.3ghz, will my CPU be a huge bottleneck if I decide to get another 4870?


Any comments / advice are appreciated.

 

[Amg]

and your powersupply is ?


again it depends what resoltuion you play and screen size or plan to get whatever.

I had two 512 in xfire till one stoped working. one isnt enough for 24inch screen tbh.

two is fine

you might lose like 5-10fps for a game like crysis otherwise you really wouldn't notice, unless you do care that much.

 

[mlcloud]

And if your e7400 was a bottleneck, what would you do?

It won't matter. You'll still play games fine. Although you should technically be able to extract a *lot* more performance out of that e7400. HIT 4ghz xD!

Edit: I realized I wasn't being very clear. The e7400 will certainly bottleneck that 4870 CF, but that's because its just monster graphic-crunching power, and it's really not a life-threatening bottleneck.

 

[Pigbearman]

I'm not a master of overclocking, so i'd have to read up a bit more on hitting the correct voltages/clocks etc etc. I have a Coolermaster HAF932 case with a Coolermaster V8 CPU cooler, and my temps are usually good (i've seen max like 42c with a full load).

Do you think it would be worth it to get another 4870?

 

[Amg]

good thing about the core 2 duos is that you can overclock the **** out of them

so if you have the cooler, try to get more out the cpu it will help your xfire by alot

 

[Pigbearman]

Well I just tried to overclock my CPU a bit more with no luck.

Here's what I tried:

#1:
CPU Clock: 10x
FSB: 340 = 3.4ghz
Vcore: 1.3375

Computer restarted once, failed OCCT within 3 seconds of the test running.

#2:
CPU Clock: 9x
FSB: 400 = 3.6ghz
Vcore: 1.3375

Computer would just restart 3 times then pop into the BIOS menu.


Any thoughts on why I can't get passed 3.33ghz? I have a very good powersupply, and I seem to be doing everything correctly.

My RAM is Mushkin DDR2-800, so I should be able to push my FSB to 400mhz right?

 

[Amg]

yeah you should

you might need to set the CPLL and the FSB termination and up the nb just a little not too much through, I m not familer with gigabyte mobos

 

[Pigbearman]

Just searched around the net trying to find a OC guide for my mobos OCing potential.

Changed one setting (System Memory Multiplier) to 2.0B.

Then tried:

CPU Clock: 9x
FSB: 400
Vcore: Auto

Started right up, went through about 20 min of OCCT with no problems. Highest temp I saw from the cores was 52c, which is fine I believe.

Who knows, maybe I can get it to 3.8ghz on air >.>