We recently did some speed testing which included SAS x32 vs x64. These involved basic desktop installations with BASE, GRAPH, STAT, IML, ETS and various Access products. To complicate matters we also upgraded our drives from HDDs to SSDs, our OS from Win7 x32 to x64 and our SAS from 9.2 to 9.4. In order to tease out the impact of various improvements and upgrades, we moved one of our SAS licenses around to 4 different systems during install, in order to see the impact various options had on speed.
With SAS 9.4 we learned we had to turn off ODS graphics before running any STAT procs or we would suffer a radical reduction in speed. Armed with that information, we developed a standardized test suite which involved thousands of uses of procs surveyselect, and surveymeans, as well as thousands of minor uses of the data step, proc sql and merges. The test suite also involved reading both SAS and Excel data and a few exports to Excel. Below are the four systems we tested and how long different configurations of SAS took on each:
Systems tested:
A) x32 i7 HDD: Dell Latitude Laptop with Intel i7-2760QM 2.4ghz CPU and WDC 7500 rpm HDD. Runing Windows 7 32-bit. Bitlocker partition on drive
B) x64 i7 SSD: Dell Latitude Laptop with Intel i7-2760QM 2.4ghz CPU and Samsung EVO 840 SSD. Running Windows 7 64-bit. Bitlocker partition on drive
C) i7 -X990 w RAID0: Sager Laptop with Intel i7-x990 3.47ghz CPU and unknown RAID 0 drive configuration. Running Windows 7 64-bit.
D) AMD FX 8350 SSD: Desktop system with AMD FX 8350 4.0ghz CPU and Samsung PRO 840 SSD. Running Windows 8.1 64-bit.

Test results:

System SAS ver. Seconds
A) 9.2 -x32 161
B) 9.4 -x64 97
C) 9.4 -x64 82
C) 9.4 -x32 85
C) 9.2 -x32 108
D) 9.4 -x64 84

What we learned:
x64 SAS runs about 3% faster than x32 (see testing on machine C).
For our application SAS 9.4 runs about 21% faster than 9.2.
A $1300 intel CPU running on Win 7 is about 2% faster than a $200 AMD chip running on Win 8.1 with a very fast drive. In this case both hard drives are very fast, but the SSD on the AMD machine proves to be about twice as fast as the RAID0 drive on the Intel machine when tested using copy and paste routines.