After noticing a possible improvement between two similar (but not identical) W7 systems both with 1GB GT240 DDR3 cards (one using 19745 drivers and one with the 25896 driver) I thought I would have a look at my Vista x64 system with its 4 GT240 cards, to see if there was any performance difference when I used the latest driver. This time I compared the 25896 drivers with the much older 19621 drivers on the 4 GT240 cards (512MB DDR5 versions).

For two task types there was little or no change between the drivers while three other tasks types ran slightly slower:

IBUCH_freebind_pYEEI, no change (+0.3%) [5 tasks/6tasks] [25896 drivers/19621 drivers]
TONI_CAPBIND, no change (+0.2%) [2 tasks/11tasks]
IBUCH_..._pYEEI, slower (-4.5%) [9 tasks/3tasks]
TONI_KIDln, slower (-3.5%) [5 tasks/7tasks]
TONI_HERGMETA, slower (-5.1%) [1 task/2tasks]

I remember some drivers causing longer run times than earlier drivers. So it is possible that the 25896 drivers are actually faster than some of the more recent drivers, released after 19621, including the 19745 drivers. The last time I tried the 19745 drivers most of the task types failed after a few seconds and it quickly got to the point that I stopped picking up tasks, so I had to uninstall those drivers and use older drivers. The19621 drivers still failed some tasks, but most worked. One positive about the 25896 drivers is that there are fewer immediate failures; I only saw 2 in 3 days, compared with 15 in 9days for the 19621.