So I figured I'd start an official mining thread for the Hd 77xx series..
Just got my first 7770 today, and I must say I'm less than impressed.. BFI_INT doesn't seem to be supported, as any miner that has it enabled, default or otherwise will just exit.
So far I have tried the DiakGCN kernel for Phoenix, as well as phatk and phatk2, tried using phoenix 1.7.4 (about to try with 2.0 rc1) and I get 131MH/s at 1000MHz, 9 aggression, vectors (just VECTORS, 2, 4 or 8 decrease performance), and worksize 128 (256 decreases slightly, and 64 makes no difference)
Using 12.2 drivers for 7700 series, SDK 2.6 (started at 2.5, read that 2.6 was better for GCN so I upgraded and it made no difference [fortunately it didn't seem to decrease my hash rate on my 6950, maybe due to the 12.2 drivers]) and Windows 7 64bit
Anybody who is able to get over 131.5MH/s at 1000MHz clock speed, PLEASE post all your specs, including miner, and the parameters fed to it.
I have a SAPPHIRE HD 7750 1GB GDDR5 LOW PROFILE (ATI chipset). I bought it because it fits in my computer and has low power drain. I run the graphics at stock GPU clock 800 MHz, Mem clock 1125 MHz. I don't overclock because the card is already running at 80C and 99% activity. I use Windows 7 Pro 64 bit 4 Gb RAM with CGWatcher v1.3.4.6 with CGMiner 3.7.2. Catalyst Version is 13.9 or 13.12, PCI Express 2.0 x16.
I run off Multipool stratum+tcp://pool1.us.multipool.us:7777.
Intensity is 11, any higher and I get HW errors. Worksize doesn't seem to make any difference. In scrypt I get around 140 kH/s and Work Utility is from 110/m to 150/m. Efficiency is around 114%.
Power drain is 45.6W (max 55W TDP).
Here are the settings:
"scrypt" : true,
"verbose" : true,
"auto-fan" : true,
"auto-gpu" : true,
"gpu-threads" : "2",
"gpu-fan" : "33-70",
"intensity" : "11",
"temp-target" : "80",
"temp-overheat" : "85",
"temp-cutoff" : "95",
"temp-hysteresis" : "3",
"thread-concurrency" : "2048",
"submit-threads" : "64"
Sometimes I blank thread-concurrency and use shaders 512 instead. The GPU doesn't seem to get as hot with thread-concurrency 2048.
Also I use my graphics card for playing games, I'm a bit weird that way.
Edit: I've found higher performance settings:
"scrypt" : true,
"verbose" : true,
"auto-fan" : true,
"auto-gpu" : true,
"gpu-threads" : "2",
"gpu-fan" : "25-70",
"gpu-engine" : "300-920"
"gpu-powertune" : "20"
"intensity" : "11",
"temp-target" : "75",
"temp-overheat" : "85",
"temp-cutoff" : "95",
"temp-hysteresis" : "3",
"thread-concurrency" : "2048",
"submit-threads" : "64"
gpu-fan is limited to 70% speed to avoid wearing out the fan.
gpu-engine can be set higher than 920, but the card and/or computer crashes. The computer must be re-booted before playing games. Otherwise the game crashes.
temp-target can be set to 80 during winter, but the card will overheat at 80 during summer. It will need to be set back to 75 during summer.
gpu-powertune is set to +20 to allow the card to use more power.
Any programs that are using a lot of CPU time will slow down the mining programs.
Now in scrypt I get around 162 kH/s and WU is around 140.
At these settings the card is temp limiting to control heat. The card can go faster if the ambient air temp is lower. 164 kH/s seems to be its peak performance.
Taking the lid off the computer case drops the temp by about 5 degrees. It's cost-effective to do mining during winter because it helps to heat the room.
What a waste of money on this junk.
Ah well at least it's a boost for my mining! I'm using Asus GPU tweak for clocking and it's pretty good. 
?