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10X G3 CPU Upgrade for PCI Macs Published: 11/02/99 |
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| The XLR8 MAChCarrier and CarrierZIF designs can be upgraded with many different ZIF CPU modules. The base card has a ZIF socket just like Apple's AIO, Beige and Blue & White G3 motherboards, which means upgrading to a faster CPU later is a snap. See my Setup Guide to the CarrierZIF for details on replacing modules.
With a ZIF socketed design, your initial card investment is protected far more than a standard CPU slot card which can't have the CPU replaced. By retaining a known reliable 'base card' there is less risk that a new card may have compatibility issues in you system. It also allows you to use recycled ZIF upgrades from Apple G3s and as time goes by, there will be more ZIF upgrades to choose from at lower cost than there will be CPU Card upgrades. XLR8's G4 trade-up discount program is also another benefit for MAChCarrier owners (see www.xlr8.com for more details). My CarrierZIF First Look article goes into more detail on the benefits so I won't repeat them here. Suffice it to say if you're in the market for a CPU slot G3 upgrade card with a future (including G4 CPU compatibility), the CarrierZIF is worth serious consideration. The extra cost of a ZIF socketed card is worth it in my opinion if you plan on keeping your Mac for some time. Although PowerLogix and Newer Technology have also announced ZIF based cards, as I'm writing this article neither are generally available. For a peek at the Powerlogix ZIF card - see my Z-Force First Look page.
After determining settings that were reliable with my Macs (I did not try to push the razor's edge), you couldn't ask for better reliability than I saw during extensive testing over two weeks. I fully exercised the card in applications tests, large program CDrom installs, copies to/from the drives and a full Retrospect backup. The MAChCarrier 500 comes as a preassembled unit combining the base CarrierZIF card and an XLR8 10X G3 500MHz CPU module, ready to install into your Mac. The card's speed switch is preset for a 50MHz bus speed and 10X bus/CPU ratio (50 x 10 = 500MHz CPU speed). The CPU is an IBM G3 CPU rated at 500MHz. The ZIF module also has 1MB of backside cache rated at 250MHz. The 10X ZIF module in this sample had jumpers to set the Bus/CPU ratio, so switches 9-12 on the CarrierZIF are ignored (they control the Bus/CPU ratio for ZIFs that are jumperless - for example Apple OEM ZIFs and many other OEM models). XLR8 responded to my original complaint that the jumpers were hard to remove; now they include extended 'tails' which would allow them to be more easily moved if you ever need to change the CPU/Bus ratio. For this 500MHz model, there is no need to change the jumpers however, as doing so would only lower the CPU speed.
Speed Settings: If you just want to run the card at the default settings you can skip this section. For those that want to experiment, the CarrierZIF design allows Bus speeds of 40 to 60MHz (documented) via XLR8's MVP (Multiple Variable Processing) switch. You can see the red switch in the photos above. It sits on the front edge just to the left of the ZIF socket. The manual has a table of settings for bus speeds and CPU speeds. There are also undocumented/unsupported switch settings for higher than 60MHz bus speeds but they will be of no use to 99.999999999999999% of Mac owners. Important Note: Along with the benefits of a wide range of adjustments comes some responsibility. This card allows setting bus/CPU speeds to rates beyond the rating of the CPU and possibly your system's capability. You need to consider the installed ZIF module's rating and the limits of your particular Mac (don't start out with high settings that have not been proven reliable in your system/CPU module combination). Overclocking may void the warranty and may not be reliable. Check with XLR8 on their current warranty policy if you plan on overclocking the card and are worried about warranty support. No company can guarantee overclocked speeds or what bus speed will be possible in your system. Note: Read my Illustrated CarrierZIF Setup Guide for more info on the base card features, speed settings, and important notes on ZIF compatibility.
Compatibility: The CarrierZIF is listed as compatible with the following Mac models [updated 6/16/99]:
I've tested MAChCarrier/CarrierZIF cards in a PowerCenter Pro (remember to disable they 7200 Graphics Accel. extension as noted in the FAQ and PF G3/Powercurve tips pages), PowerTower Pro 180 (L2 cache dimm removed), 9600/350 and Genesis here successfully. As noted previously I suggest PowerTower Pro 225/250 owners contact XLR8 to ensure their motherboard models are compatible (this should not be an issue now, but just in case). Retrospect Compatibility: I also verified that Retrospect 4.0 backups were error-free. With 'Speculative Processing' disabled a complete backup of a 4GB boot volume in the 9600/350 completed without errors (including verification). The XLR8 control panel default setting for 'Speculative Processing' (often called 'Branch Prediction') is disabled. Dantz (makers of Retrospect) Tech Note 414 reports there is a problem with all pre-Apple G3 systems onboard Ethernet unless you are running the Ethernet extensions from OS 8.6. They also recommend disabling Speculative Processing if you are doing backups or large file copies over a network as a precaution. on the applications performance page you'll see in some cases that setting actually increased performance. Retrospect was the only application I saw that required it, but there could be others that I've not used. I have not tested Adaptec wide SCSI card compatibility but XLR8 has a Tech Note on how to use their software with these cards. The tests in the PowerCenter Pro using the OEM 2930B (narrow SCSI) card showed no problems. More information on compatibility issues with other G3 CPU upgrades, see the comments on my CarrierZIF First Look page, the CPU Upgrades area of my FAQ and CPU Reviews page.
System Compatibility/Stability Tests: Here is a summary of my tests to date with three different XLR8 MAChCarrier/CarrierZIF design cards in four different Mac systems, each chosen for a particular reason:
Overall, the CarrierZIF design has been one of the best CPU slot cards I've ever tested. I can say without a doubt I consider it at the top of the heap of CPU slot cards I've seen to date. For other CarrierZIF owner reports, see my Rate Your G3 Upgrade database. As with all CPU upgrades, often times on inquiry I find out there may have been a L2 cache, RAM, speed settings (Bus or CPU speed too high), reversed heatsink clip (see my Setup Guide) or other reason for problems reported, but the database is still a valuable tool with over 2500 reports as of November 1, 1999. I stress that owners of any card should use it for several weeks at least before posting an entry and always remember to read the manual completely before installation. If there are problems - contact the card vendor immediately, they often can provide a solution or identify the source of the problem. Test Systems Hardware Summary
For reviews of MAChCarrier 450 and various ZIF upgrades in CarrierZIF cards with other Mac models, see my CPU Cards page. And as mentioned previously, you can see what other owners had to day about the CarrierZIF or other upgrades in my searchable Rate Your G3 Upgrade database.
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| Summary: The hardware design has proven reliable in use, able to run higher bus speeds that any previous card I've tested and very fast. With stable operation at up to 60MHz bus speeds in some test machines, a unique ZIF socket to allow for future upgrades (a first), the CarrierZIF design is currently the one to beat.
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| The next page contains a summary and final comments on the product. | |
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Intro | Benchmarks | Appl. Tests | Software Controls | Docs/Installation | Specs/Design | Summary - or - |
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Copyright © Mike, 1999. Users of the web site must read and are bound by the terms and conditions of use. |