Adapting to Parallelism: Catalyst 5.12 More Dual Core Friendly?

Performance Comparison: Dual Core vs. Single Core

The next step in our performance analysis is to look at the improvement we get when moving to dual core from single core. These will likely be the numbers ATI quotes in their marketing literature, as they will show the gain in performance with a particular driver when moving from a single core environment to a dual core. These numbers have the potential to be large because the games themselves could benefit from dual core processors (though not many do).

We will be able to spot games that already get a performance boost from dual core due to our Catalyst 5.11 data. The 5.11 driver doesn't have multiprocessing optimizations, so games that show a performance boost under this driver are getting that performance boost from the way the game is written. Combining this knowledge with what we learned in the previous section should help us understand where ATI has succeeded and where they still need some work.

Dual core processing lends a hand to the 5.11 driver at 10x7, and has a bigger effect at 1600x1200 than it does on the 5.12 driver. But at 800x600 the 5.12 driver performs much better when running on a dual core system, especially when compared to the performance drop on the 5.11 drivers.

Battlefield 2 Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	-2.98	3.45	1.9
Catalyst 5.12 (Beta)	18.19	6.66	0.84

Enabling 4xAA takes away any real advanage in scaling the 5.12 driver had over the 5.11 catalyst. Combine this with the fact that the 5.12 just performs worse than the 5.11 driver with 4xAA, and anyone who plays BF2 with AA on will not be to pleased.

Battlefield 2 4xAA Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	2.12	-0.91	1.49
Catalyst 5.12 (Beta)	2.8	1.87	1.2

We can plainly see that dual core helps the 5.12 driver and not the 5.11 driver under Day of Defeat with no AA. These are some good gains, especialy in light of how well the 5.12 does compared to the 5.11 (as seen on the previous page).

Day of Defeat Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	0.37	0.37	0.22
Catalyst 5.12 (Beta)	6.51	6.54	1.52

Even with 4xAA on the 5.12 driver scales well with CPU power. most impressive is the nearly 3% gain at 1600x1200.

Day of Defeat 4xAA Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	0.56	0.38	0
Catalyst 5.12 (Beta)	6.89	4.5	2.93

The table for FarCry lets us know that both drivers seem to benefit from dual core processing. The 5.12 driver certainly improves the leap over single core performance, but not all the glory should go to the new dirver. The larger percent increase can be attributed to the game itself benefiting from dual core systesm

FarCry Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	4.64	3.35	0.74
Catalyst 5.12 (Beta)	12.44	6.95	3.99

The returns are a little diminshed with 4xAA enabled, but its easy to see that there is still more of a benefit under the 5.12 drivers.

FarCry 4xAA Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	3.04	2.26	-0.19
Catalyst 5.12 (Beta)	7.5	5.7	0.57

These two tests again show no performance difference or issue.

Quake 4 Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	0.27	0	-0.47
Catalyst 5.12 (Beta)	0.27	0	-0.16

Quake 4 4xAA Percent Increase (Single core to Dual)
	800x600	1024x768	1600x1200
Catalyst 5.11	0.21	0.17	0
Catalyst 5.12 (Beta)	-0.21	0	0