First test of the GigaDesign 2GHz G4 upgrade card

[MacBytes]

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Category: 3rd Party Hardware
Link: First test of the GigaDesign 2GHz G4 upgrade card (http://www.macbytes.com/link.php?sid=20050414103329)

Posted on MacBytes.com (http://www.macbytes.com)
Approved by Mudbug

[shamino]

Using Google's translation of the main article, I find one thing particularly interesting.

For many tests, this 2GHz G4 upgrade performs only slightly better than an Apple-native 1.53GHz box. This is because the 1.53 box is using a PPC 745x-series processor with L3 cache, and the GigaDesign chip is using a 7447, with no L3 cache.

That cache makes a big difference in performance.

Hopefully, they will manage to make a version of this upgrade that has an L3 cache (and dual-processors). That would make for a nice upgrade to my QuickSilver box.

[eric67]

Using Google's translation of the main article, I find one thing particularly interesting.

For many tests, this 2GHz G4 upgrade performs only slightly better than an Apple-native 1.53GHz box. This is because the 1.53 box is using a PPC 745x-series processor with L3 cache, and the GigaDesign chip is using a 7447, with no L3 cache.

That cache makes a big difference in performance.

Hopefully, they will manage to make a version of this upgrade that has an L3 cache (and dual-processors). That would make for a nice upgrade to my QuickSilver box.
7447A processor does not support L3 cache. it is missing the controller necessary for this purpose.

[shamino]

7447A processor does not support L3 cache. it is missing the controller necessary for this purpose.
Did I say otherwise?

My point is simply that, by basing their upgrade card on a 7447 instead of on a 745x, they are seriously crippling its performance. And they make it almost useless as an upgrade for those users whose Macs have 745x processors in them (like my dual 1GHz system.)

I'm sure there are technical reasons why nobody has shipped a 745x upgrade card at the newer 1.7GHz (or overclocked to 2GHz) speeds, but that's not my problem.