You're right... But he's still got insufficient memory for attempting a triple-buffered configuration. I just got the calculations off. He's still going to probably need 1.5 Gb at least. Let me mull over the best way to express what I'm trying to say here and I'll put it up here in a bit.
1920x1200 pixels = 2304000 pixels
@ 4 bytes per pixel make that 9216000 bytes yeh?
divide by 1048576 for megabytes and I get the magic number of
8.8 MBytes per frame buffer.
For three screens that gives me 26.37 MBytes for frame store.
Make that 79.10MBytes for a triple buffered configuration without rendering overhead.
Now consider the "alternative" vendor which did provide a frame locked Compiz desktop with frame locked video playback.
nVidia 9800GT 512M driving 2 x 1920x1200
That's 512M driving 2/3 of the pixels the ATI's 1GB is driving.
Going by nVidia's numbers there's the possibly of being able to drive four of those screens with 1GB.
Am I missing something in my numbers?
Question; Is it actually necessary to store the alpha channel?
Maybe amd wants to sell new cards with more vram Usually only vram is splitted when you use a multi gpu card. I guess that's a programming error. Without official beta builds of the next driver you just have to wait several weeks till you can try again. I really hate that way because the error you found should have been found much earlier. But from the comments it seems that the new tearfree mode has got problems with powersave states (otherwise it would be unlogical that glxgears could help anything). I still will not use my amd card on my main system until those bugs are resolved. Basically my hd5670 would be faster than my gt220 but there are too many drawbacks still.
Getting back on topic: I finally got around to installing this new driver and enabling the "tear-free" thing.
I still get tearing on my desktop windows now that I've enabled the feature, but it seems to "fix" itself when I move the mouse cursor around. That part's new.
I hate my ATI HD5750. I only bought it because of the promise of adequate open source drivers in the near future, but I've hated it ever since I first installed it. I miss my old Nvidia card. It was outdated and slow, but my desktop always looked great. I wish I could afford to buy a new video card and get rid of this trash.