4890 HD Crossfire + 3DMark Scores

3DMARK isn't a very good software to test your performance,games are better,and when u say Crysis runs fine then i think u don't have any problems,also yes 3DMARK 06 is CPU limited too,so that maybe the reason

Ok i OC'ed the cpu to 3ghz... got much better results  

3DMARK VANTAGE
--------------
3DMarks: 17991
CPU Score: 18442
Graphics Score: 17845


3DMARK 06
---------
3DMarks: 20542
SM 2.0 Score: 7584
SM 3.0 Score: 10667
CPU Score: 5252

Nice, i was about to tell you to do this   2.6ghz is a bottleneck ...

Stress test and be sure its stable and stay under 80c full load with small FFT

I have virtually the same setup as you (GB 4890 OC x 2, 920) with the P6T and only 6Gb or Ram, and was worried about low 3dmarks06 scores (around 18k or so). I also found that overclocking the 920 to ~3.1-3.2Ghz increased my scores quite significantly. Was able to do that on stock cooling for the CPU too so basically a free upgrade  

I set the cpu bus to 165 mhz at x18 for a 2984 mhz to make the ram 663x2 at x8 so roughly 1333. I wanted to get the ram up a little as its 1600 ram and 1066 seemed a waste... i didn't want to overload the cpu with the stock cooler either but wanted a small boost to test. (not sure if these settings are ideal... i would love some thoughts from others on this)

my very first i7 so its all very new and different to OC heh but the temps are:
45/43/45/41 idle
74/72/72/70 after running the vantage cpu physics test (load-ish)
(using realtemp)

so i might be able to make it a 3.2 at most but 3.0 might be best, just worried if i'll have to inc voltage too or if "auto" will take care of it heh... and i need to run a proper burn-in app of course.

I'm also in australia so the humidity and heat can get the ambient nicely high  

I'll see about investing in a nice cooler however and run at 3.4-3.6 its a D0 stepping cpu which is aparently nice for OC so i should be good to do that.

Thanks for the replies! if anyone has good ideas on coolers let me know  

Take a look at anandtech.com. they have nice CPU cooler review.

At first I only managed a 3Dmark 06 score of 18K with two 4890s in crossfire. Overclocked my 955 to 3.8 and my score went up to 21K.

AMD Phenom II x4 955BE @3.8Ghz
Xigmatec Dark Knight
Asus M4A79T Delux
G.Skill DDR3 4GB 1600Mhz
2x Asus Radeons EAH4890/Crossfire
CM Storm Scout
Antec Quattro 1000W

i wouldn't trust those tests
especially when it comes to ati cards
futuremark and nvidia physx seem to be best friends