The debut of the Power Mac G5s may seem like a death knell to Giga Designs, PowerLogix and Sonnet, but they see the situation in a different light. With an entry price of $2000, the G5 is still out of the reach of many gamers, though it's drool-inducing power and style is reason enough for some to break open their piggy banks and endure a spartan lifestyle for a while. Besides affordability, others may choose to pass on the G5 to avoid revision one cooties and keep Mac OS 9 compatibility,
The processor upgrade route is made more attractive by constantly declining prices. Since IMG's first comparison article was published in February, the 800 MHz and 1 GHz parts have each dropped over 30%. The $600 that bought you a 1.25 GHz G4 five months ago now buys you a G4 that is 200 MHz faster. In addition, Other World Computing has entered the competition with their Mercury Extreme upgrades.
Not New, but ImprovedGiga Designs is looking to raise the price/performance bar once again with their new G-celerator G4/1 GHz (GC5A-1000-S2) upgrade for AGP equipped Power Mac G4s. Pre-tested at 1.2 GHz, the GC5A-1000-S2 is reminiscent of PowerLogix' first G3 upgrade cards, which had great overclocking potential. It uses Motorola's PowerPC 7455A processor and 2 MB of synchronous pipeline burst (SPB) cache, running at 1/4 the processor speed (250 MHz at 1 GHz, 300 MHz at 1.2 GHz). DDR L3 cache is only marginally faster than SPB cache but it is much more expensive and less cost effective. Giga Designs decreased the processor/cache ratio (thus increasing the L3 cache clock speed) to gain some performance.
Upon receiving the upgrade, I immediately set the jumpers to 1.2 GHz. The G-celerator proved to be perfectly stable at this speed throughout extensive "testing". Out of curiosity, I increased the CPU multiplier to 13x and surprisingly enough, there were no hiccups at 1.3 GHz! A 30% increase in megahertz won't translate into a 30% increase in real world performance, but it is still an impressive overclock, especially for a G4 processor.
3D BenchmarksOnce again, my trusty (but frustratingly slow) G4/500 Sawtooth served as the test mule. Below are the particulars of the hardware and software configurations I used:
• G4/500 (AGP Graphics)
• ATI Radeon 8500
• M-Audio Revolution 7.1
• 1 GB PC100 SDRAM
• Seagate Barracuda IV 80 GB HD
• Mac OS X 10.2.6
• Quake 3: Arena 1.32, demo four
• Jedi Knight II 1.04, demo jk2ffa
• Unreal Tournament 2003 Demo (with OpenAL fix), antalus botmatch
I used "normal" quality settings in all benchmarks to minimize the effect of the graphics card and isolate CPU performance.