XLR8 MAChSpeed G4z 500 MPe
ZIF upgrade card for all Macs with ZIF socket.

The MPe comes in a box containing the following items: Antistatic wrist wrap of very high quality (not a disposable one), thermal paste, a small stick to apply the paste to the CPU, a screwdriver to remove the clip holding the heatsink, several jumpers to set the CPU/Bus ratio and an antistatic plastic box containing the CPU upgrade card. Also included are a nice printed manual in English (by the time you read this, a localized version may be available, according to XLR8) and a CD-ROM containing the software and information in various languages

Special about the MPe is that it is SMP enabled, which means that you can plug it into a Dual ZIF upgrade card that is now also available from XLR8. XLR8 claims to be the only company to supply its customers with G4/Altivec plug-ins for Photoshop 4 and 5. For 5.5 you are supposed to take the Adobe ones, which I did. The card seems to be fabricated very carefully, the CPU is partially covered by a rubber buffer that helps ensure heat dissipation and protects the chip from damage through the heat sink. The pins are gold coated, for minimal resistance (as are Apple's) and the jumpers can be set easily, also when the heatsink is already mounted on top of the CPU. This should please all the overclockers out there: just open the machine and change the settings, no annoying unmounting and remounting of the heatsink required. The G4 used was of revision 2.9, that's very recent.

The software makes a very finished impression, not only is it very stable, it also offers plenty of additional features, for example setting the backside cache, thermal monitoring, write-through options etc. It's clearly the fastest software I tested so far. Very nice: the software also works with non-XLR8 CPU upgrades. More on that soon.

The manual includes a quickstart and detailed information on installation in machines it works with. There are also some tips on optimizing performance, overclocking (yes, they actually tell you how) and various other things you might run into.

Installation is a breeze, as with all ZIF modules and the CPU runs amazingly cool. With carefully applied thermal paste, heatsink and an extra fan on top of the heatsink, as shown below, I was able to bring the startup temperature of the chip down to 15°C at room temperature of 22°C. Of course those temp readings aren't very accurate:). Anyway. Running all those tests the chip never surpassed the 39°C mark, and that's great for a G4.Typical temperatures were between 27 and 31°C idling and in use respectively.
( XLR8 says the G4 can run at temperatures up to 76°C before it starts to cause problems.)

Overclocking was a joy with this unit: The machine ran perfectly stable at 533/66/33 in the Beige G3 with 2:1 settings, but refused to boot up with 525/70/35, which I find interesting. 600/66/33 didn't return a POST (no happy Mac). In the Blue & White G3 the CPU even clocked up to 550 MHz running the backsidecache at 2:1, but was very unstable, so I had to abort testing. Running at a 2.5:1 setting it was more stable, yet still not stable enough to be really satisfiying, but good enough to run most tests. Understandably I didn't test 600Mhz, after failing to achieve those on the Beige already. Overclocking to 533 only raised temperatures marginally, while the same chip runs considerably hotter in the Blue & White G3, most certainly because air flow isn't as good and the heatsink is smaller. Trying 566/66/33 would have made sense, but since that's a 8.5x multiplier on the 66MHz Bus, it can't be selected, as this multiplier aparently doesn't exist on either G3 or G4.

Overall a very satisfying product combining ease of use with professional choice and lightning fast software, what else do you want?


  • excellent hardware design
  • excellent, fast and stable software
  • overclockable
  • excellent equipment


  • rather high price

Images of this card

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