|If you're new to
Overclocking and not sure what to do, check out these two excellent
Guides for some pointers:|
Overclocking the CPU and Memory
Overclocking the Videocard
Diamond Multimedia's Viper Radeon HD 2900XT videocard comes out of the box
with a GPU running at 743MHz, memory clocked at a cool 1000MHz. (AMD reports DDR value, that's 2 GHz in SDR).
By all accounts that's already faster than most graphics cards, but not
fast enough to dissuade PCSTATS from overclocking the Radeon HD 2900XT GPU and its cadre of GDDR4 memory even further!
Starting with a single videocard, the
AMD Radeon HD 2900XT GPU was overclocked in 5 MHz increments, starting from 743
MHz. This is uncharted territory for PCSTATS, for sure. The Radeon HD 2900XT handled this well,
and broke the 800 MHz mark without sweat.
The AMD Radeon HD 2900XT core ran out of steam once
it hit 825 MHz, anything higher and the system would lock up while running benchmarks.
Still 825 MHz is a decent jump from 743 MHz.
Next up was the 1GB of GDDR4 memory, clocked at an even 1
GHz. The memory frequency was increased in 10 MHz jumps,
easily breaking past 1100 MHz. That is the stock speed of the memory on the 512MB
version of the Diamond Viper Radeon HD 2900XT videocard. Continuing, the memory topped out at
1135 MHz, anything higher it locked up while running benchmarks.
Crossfire Overclocking Tests
Next up PCSTATS tried our hand at overclocking
two Diamond Viper Radeon HD 2900XT 1GB videocards running CrossFire mode. That's about $900 in videocard if you're counting!
;-) I started with the core, but kept my expectations low as I figured
the cards would not reach the same overclock as a single Diamond Viper Radeon HD 2900XT
is capable of. I was right. The VPU reached a maximum speed of 812 MHz, still
not too bad though.
The memory did not overclock
as well in Crossfire mode, and to make a long story short we saw top
speed results of 1123 MHz. That's just 12 MHz shy of what the lone Diamond Viper Radeon HD 2900XT
So there you have it, overclocking results for a single
Radeon HD 2900XT and two running in Crossfire.
As you'll see in the benchmarks, overclocking under Crossfire can have a very significant impact
on game performance, whether it's worth the added cost is another matter entirely however. Anyhow, on with
Prelude to Benchmarks
how the Diamond Viper
Radeon HD 2900XT 1GB videocard test system was configured for benchmarking;
the specific hardware, software drivers, operating system and benchmark
versions are indicated below. In the second column are the general specs
for the reference platforms this pair of ATI Radeon HD 2900XT based
videocards are to be compared against. Please take a moment to look over PCSTATS
test system configurations before moving on to the individual benchmark results
on the next page.
|PCSTATS Test System Configurations|