No, there should be no pci-e bandwidth limitations because only a few bytes and the program code is transferred over pci-e. The quoted performance was for a factory overclocked 280X, so subtract 10% to get a performance estimate for a reference card. I used Catalyst 13.12 because Catalyst 14.4 was slower.
Yes.. i acknowledge that.. NaN.. but my overclock simply... slowed down my timings plus some errors/instability I might be having... due to high voltage.. CPU+GPU latency... to get better CPU+RAM throughput... and CPU overclock... so.. in my case.. and my board.. I know I have some limitations.. but.. I have done some tests over the other boards (Zxx) and the performance quite goes further up.. with same GPU cards...
Another big detail.. is that I am using a test system with a CPU+BOARD+RAM.. that is running for............ well.. since 2009... 24/7... only the CPU changed... once... free upgrade... to xeon. So.. it might have some issues.. It's ok.. for a 30 day... loop (system restart + WC water refill + windows updates + other hardware experiences)..
I might have a new test board.. by August.. or September... for free.. so by then.. I will have updated performance metrics... tests... tuning.. etc... one thing is for sure.. I have never had.. a system that could last so much!.. nor I think I will have it again.. 5 years!! and counting!
keep up... catalyst 14 is only good for 290X.. or 290.. the others.. are still optimized for catalyst 13... but.. things... will change.. =) new specs... of 3xx series... will come by end of 2014 =) I found them promising.. since AMD.. understood finally! that DP.. has to go UP UP UP..
EDIT:My command lines (due my conditions.. this were the best 5 hours.. specs/attributes..):
290X
clpts_x86-64.exe -o 6 -u XXX:XXX -t 0,0 -a 1
270X
clpts_x86-64.exe -o 6 -u XXX:XXX -t 1 -a 1