I bought one of these cards recently and I'm very happy with it. Good bang for the buck. MSI Afterburner works with the Vapor-X and you can use that to go beyond the 960 MHz maximum limit that the Catalyst CC uses for this card. Just add this to the MSIAfterburner.cfg configuration file:
EnableUnofficialOverclocking = 1
1050 MHz on the core is easy enough with some additional voltage. I tried 1100 MHz too but it wasn't stable and was going to need more voltage than I wanted to use.
The other option is to flash to the Asus 5770 bios which I also did.
http://www.xtremesystems.org/forums/showthread.php?t=237414
This gets rid of the 960 MHz limit in Catalyst and you can then go as high as 1200 MHz in CCC. For 24/7 use I just use 1000 MHz for the core which is fine at default voltage. MSI Afterburner works but it kills the 2D clocks so 1000 MHz / 1300 MHz is good enough for me.
Here's what you need to watch out for. Sapphire is shipping two completely different versions of this card with the same part number. The one I got does not come with the Dirt2 voucher and comes with completely different Samsung memory chips. These chips are not nearly as good as the Hynix memory chips that were on the card that W1zzard tested for this review. I run them at 1300 MHz but 1400 MHz or beyond just isn't possible with the Samsung memory. A little disappointed but ultimate performance isn't that important to me.
What is important is sound level. Even when overclocked I can have the fan speed locked to 20% in CCC which is equivalent to about 1100 rpm. Same noise level in 2D or 3D. The first gaming card that is dead silent. I have to put my finger on the fan at this speed just to make sure it is still turning because I can't hear it. I love it.
Edit: There is a new hotfix driver out that addresses the gray screen issues that some users have seen. It is designed for the 5800 series at the moment but this fix should help out the 5700 cards too when the driver for them is ready. I've only seen this once while doing some aggressive overclocking. I tried installing the 5800 download but it screwed things up so I had to play musical drivers and go back to the original.
Here's a picture of my Vapor-X 5770 with the Samsung memory and the same part number and the same SKU number. Paying extra for the Dirt2 voucher seems to get you the better Hynix memory chips.
Edit: I noticed that the MSI Radeon HD 5770 Hawk that was tested also uses these exact same Samsung K4G10325FE-HC04 memory chips that are rated at 1250 MHz. The Samsung memory chips on the Hawk did a little better than the Samsung chips on my Vapor-X. Increasing the GPU core speed will get you a bigger increase in performance compared to increasing the memory speed.
[url]http://img697.imageshack.us/img697/245/vaporx5770samsung.th.jpg[/URL]
Here it is after running 3DMark06.
http://img3.imageshack.us/img3/4215/vaporx3dmark06.png
Using Afterburner I kept bumping the core voltage up +0.025 until it was stable. 1050 MHz took 1.275 volts which is typical for these cards. The memory was stable enough at 1350 MHz to complete 3DMark06 but it's not stable at 1400+ MHz like the Hynix chips are. It's a Sapphire 5770 Vapor-X but it's been flashed with the Asus bios so that's why it reports Asus. By default, both versions of the Vapor-X use the same bios.
