New box with an 8-core AMD FX-8150, an NVIDIA GTX 570 and 4 Gbytes of memory at 1333 MHz arrived. After a few problems with perceus (rejected hardware address starting from 8C:…), all else appear to have worked smoothly. Started testing it with NAMD and comparing it with the i7-extreme-GTX295 machine (all measurements in nanoseconds per day) …

Multicore version (Non-CUDA) v.2.8

The multicore NAMD version used for the i7 and Q6600 machines was somewhat older than the one used for the AMD machine. To be on the safe side, subtract ~10-20% from the speedups quoted below.

		AMD 8-core		i7, eight threads	Percent faster		Q6600-based quad	Percent faster
100K (ApoA1)		0.40		0.33	23%		0.19	116%
60K atoms		2.18		1.61	35%		0.95	130%
25K atoms		6.25		4.35	43%		2.53	147%
6.5K atoms		24.0		15.4	55%		9.8	145%
1.6K atoms		108		79.4	36%		48	125%
0.9K atoms		192		145	32%		82	134%

With CUDA

For the AMD-GTX570 machine and for large problems (~100K atoms), adding a line in the spirit of +devices 0,0,0,0,… significantly improved performance. This was not the case with the i7-GTX295 hardware.

	AMD 8-core FX-8150 + GTX 570	i7 extreme + GTX295, four threads
100K (ApoA1)	2.33 (with '+devices')	1.92
60K atoms	5.98 (with '+devices')	6.28
25K atoms	13.7	12.2
8.1K atoms	37	25
1.6K atoms	172	166

Other comparisons

5.5K atoms → 56 ns/day on FX-8150+GTX570 (CUDA) vs. 32 ns/day on Q6600+GTX460 (CUDA)
4.5K atoms → 68 ns/day on FX-8150+GTX570 (CUDA) vs. 25 ns/day on two Q6600 (8 cores, no CUDA) vs. 19 ns/day on one Q6600 (4 cores, no CUDA)