Upgrading an old B&W G3 Mac for use with ffmpegX

[adamantius]

Hello!

I've been getting a surprising amount of success in converting mpeg2 to mpeg4 .avi's, and back, on a very definitely Legacy Mac.

Yesterday I damaged the motherboard on my old souped-up PM 8600 with a Sonnet Crescendo G4 processor and Radeon video, and I figure it's only a [short] matter of time before it dies completely.

I have access to a free B&W G3 mac, which can use nearly all of my old hardware from the other machine, but it'll need a different processor upgrade if I want to do the kind of video work I'd been doing. My options for this machine appear to be a Sonnet Encore/ZIF G4 running at 1 GHz, or one of a few different XLR8 or PowerLogix G3 CPU upgrades which run at 1.1 GHz.

As far as I can tell, the choice boils down to one of the following:

a G4 processor (Sonnet) which will run at 1 GHz, with the AltiVec optimization of ffmpeg I've taken advantage of in the past, but also clocking down my system bus speed from its native 100 MHz to 66 MHz, and with a L2 or L3 processor cache speed of 250 MHz.

a G3 processor (either XLR8 or PowerLogix) running at 1.1 GHz (with the possibility even of some discreet overclocking, which the Sonnet won't allow), a L2 cache speed of 1.1 GHz, the native system bus of the machine remaining at 100 MHz... also somewhat cheaper than the Sonnet card... but with no AltiVec optimization.

So each involves a theoretical sacrifice. Which can I more easily afford to lose as a video tinkerer? Is the AltiVec worth the reduced system bus speed, the reduced L2/L3 cache speed, the slightly lower CPU speed, and the slightly higher cost, or am I better off with a cheaper and faster processor with a faster system bus and L2/L3 cache, and no AltiVec optimization?

To complicate matters, I gather that the new Intel Macs have no AltiVec functionality, and don't do as well for video processing as the G4's and G5's that do have it, but it seems likely that newer versions of the OS won't contain AltiVec code.

So, any advice on how to proceed? I'm sure there'll be many highly experienced and well-intended people who'll advise me to just get a newer Mac, and I should and will, but it's just not an option right now. My options are as stated above; I just wish it didn't seem so much like flipping a coin.

Any advice would be much appreciated, and thanks for reading this far!

[thoughton]

On Amazon the Sonnet 1.0GHz G4 upgrade is around $340.

A 1.25GHz Mac Mini is $499.

I know which one I'd buy It does however depend what accessories you have and do they need to be internally mounted.