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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 Improved Giga 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 Benchmarks Once 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.
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