Ok so i have the EVGA GTX Geforce 550 Ti (2GB) and it's slow I mean i thought this card could run all games on at least high. But, I ran DayZ 33 Fps at times with Low everything & i record for Youtube so thats a problem with Fraps it gets to like 22 Fps which is literally unplayable! So i've overclocked it from 900Mhz - 1100Mhz & it's better and it's stable, also the memory is clocked from 2004Mhz - 2220Mhz all this using EVGA precision X. This is considered good from what I've seen on other places. My degress in Celcius is 38C Idle & 59C - 60C under Load, but my problem is it has a throttle back! it says in CPU-Z that its at the 1100Mhz & 2220Mhz mark. But when i put it under the EVGA OC scanner X (as well as in the Precision X) it throttles it back to 999Mhz & 2197Mhz! My system has 2 intake fans and 2 exhaust I don't know why it's clocking it down so hard if it hasn't even gone above 70C PLZ HELP (Also i got it to go 1050Mhz for awhile then it just downclocked once i reopened program the C was only like 38C it was idling at the time).
Buying GPUs is always a gamble too, it is the luck of the draw sometimes you'll get a GPU that can push a little further then what they say and some go a little less then what is said. Your GPU is at the age to just sell it and get a much better one, buy some nice $200 one or so you will see an improvement. There is really nothing that you can do to make it perform better.
i too have a 550ti and wonder, would it be worth 90$ to try sli or is that chucking 90$. which is half a 7850. ive heard mixed reviews regarding sli
The clocks dropping might be a matter or unstable power or low voltage, there is nothing you can do about the low voltage, for the unstable power i recomment taking out the PSU and measuring the out put voltages with multimeter. !!Be Sure what your doing!!
There is no point using such low price card on SLI, it is mainly desinged on top of the class cards like GTX 670, GTX 680 or GTX 690 anything lower than that should not be used cause you can get 1 class higher card much cheaper and benefit from lower power consumation etc.