pretty sad really...both my gts 450, and 660ti are working on the same WU8074. it says the gts 450 is averaging is 26149ppd with a time per frame of 2 mins 07 secs, and that the 660ti is averaging 10204ppd with a time per frame of 5 mins 27 secs
kinda messed up that a $300 higher end video card is getting its a$$ handed to it by a card 2 generations old that was a LOW end card to begin with..
Woah... wait a minute... Even with core version 2.22, there's no way a GTS-450 is getting anywhere near 20,000ppd on p8074, & core version 2.25 runs about 30-40% slower on Fermi cards. I think you have your numbers backwards. 26,149ppd is about where the 660Ti should be, 10,204ppd is about where the GTS-450 should be.
On Fermi cards, GPU ppd scales pretty evenly with the number of Cuda cores. At 92 cores, my GT-430 gets about 6,000ppd for about 65ppd per cuda core, At its best, my GTX-460 with 336 cores is getting 2min 56sec per frame for 19,017ppd (average is 17,600 - not sure why the big gap between best & average outputs...) for about 56.6ppd per cuda core. Lets assume that my 460 is performing poorly & my GT-430 is performing about where it should, given the clock speed difference between the 430 & 450, that should put a 450 between 68 & 76ppd per Cuda core depending on overclock. Going with the high-end, your 450 has 192 cuda cores time 76 = 14,592ppd. But even going nuts & assuming you're getting an astounding 100ppd per cuda core, that still leaves you just 19,200ppd...