=Summary=    PROS: Fast, excellent value. Remote Speed Control makes tuning for max performance                   easy. Largest range of speeds available.    CONS: None significant. MacBench 4.0 scores
Intro:
Value. Call it "bang for the buck" or $/Mhz if you like, but that's what immediately came to mind when testing this card. It delivers a lot of performance for the money, and is an exceptional value for those looking to upgrade their Mac's into the 200mhz and over club. As stated in the Powerboost Pro 233mhz review nothing else out there currently comes close to the range of settings or the ease of adjustment the PowerBoost Pro offers. This card will allow you to get the maximum performance out of your PowerMac with a minimum of work, period. Forgive the fact that this review is a little shorter than most, but a recent personal tragedy has been very stressful and I am not able to make this review as detailed as I'd like. However I felt I should bring the product to your attention, and it has helped to take my mind off more serious matters. Since this card is identical to the Powerboost Pro 233mhz review differing only in the CPU rated speed, I'll repeat those observations here for those that have not read that review. Performance: Due to personal demands on my time, I limited testing to my installed 1 meg PowerLogix 1meg RapidCache. The top speeds I was able to reach reliably with the 200 card were 54.33mhz bus/217.32 mhz cpu (x4 bus/cpu ratio setting). At 55mhz bus/220 mhz cpu the card ran the full MacBench 4.0 tests fine, but I saw one Type 1 error when rotating a large image in Photoshop - so I reduced the bus speed setting two clicks and no further problems were encountered. Performance was excellent as noted in the MacBench scores below. Compared to a identically equipped 8500/120 (with the same 1meg L2 cache) CPU performance were boosted 78%, FPU by 105%, disk by 17% and video performance was increased by an incredible 91% (almost doubled).
Description
The PowerBoostTM 200 "Pro" package contains the 604E processor card and a small velcro backed Remote Control that attaches easily to the card. With the generous length of the connecting cable and adhesive-backed velcro attaching method, the remote could easily be mounted on the back of the Mac if desired. The manual has photos of typical installations, a treatise on bus speeds and ratios, and a complete table of switch settings for 40mhz to 70mhz bus speeds. Bus Speeds, Ratios and Cache explained: The bus speed of your Mac determines how fast the the main Input/Output systems communicate with each other (ram/PCI/scsi), and is the main bottleneck in the current Macintosh motherboard designs. Think of it as a pipe size, limiting flow of information to other areas from the CPU. In general the faster the bus speed you can run, the better overall performance you will obtain. Unlike most other upgrade cards, the PowerBoost Pro's ease and range of adjustment allows maximum efficiency. Cache - why bigger is better The bus speed bottleneck is why cache is so important, as cache buffers the CPU from this slower "pipe". Cache contains very fast specialized ram that allows the CPU to run at its full speed without waiting on slower devices like Ram and disks. The larger the cache the better able it is to keep a fast CPU "fed" so to speak. When data is not in the cache, the CPU must wait on slower ram or disk access to process data.
Setting up the Pro:
There are two adjustments that are used to maximize performance with the Pro; bus speed and bus/cpu ratio. First you choose the bus to cpu ratio (usually 4:1 for a 200mhz card). This multiplier of the bus speed determines the speed of the CPU. For instance if you run a 55mhz bus speed with the 4:1 setting, you would run the CPU at 220mhz. Changing the speeds is as easy as shutting down and rotating the adjustment knows on the remote control one click higher or lower. The manual provides a complete table of all speeds and their corresponding switch settings. Finding the Max Speed - Easier to do than to describe: I know it may sound confusing or complicated - this search for the maximum speed of your Mac. However with this card it is very simple. You start at a default setting (say 50mhz bus 4:1 ratio setting). That's a 200mhz cpu speed, and it is always best to start low and work up. Now you simply boot the Mac, and test for reliable operation. We followed a standard procedure of running the Newer Clockometer, Newer Ram test{run 5 times}, then a full MacBench 4.0 test series. If no errors were encountered, we raised the bus speed. If errors were reported, we reduced the bus speed one click and retested. Once the maximum speed is determined, then we run the Mac for at least 24 hours to determine if it is still reliable. Since shutting down and moving the remote control knob one click is all it takes per cycle (no removing the card to adjust speeds), this exercise is fast and painless. I recommend you start with the PowerBoost Pro 200 set for the 4:1 bus ratio setting and with the bus speed switches set to 50mhz (adjusted by this knob) and then search for the maximum bus speed buy booting the Mac, running some sample applications to verify reliability ( a Ram Test, games and Quicktime video seem to be good indicators that all is well). To prevent your stock L2 cache from limiting the bus speed and performance of the card, I highly recommend the PowerLogix 1 meg cache upgrade, as it alone is worth about 25% in performance boost and should be the first place you start to upgrade your Mac's performance. For a tutorial on how to upgrade the cache in a 8500, see my Step-by-Step Tutorial. The Powerlogix 1 meg Rapidcache will help remove the stock L2 cache bottleneck from your system, which even with other companies aftermarket L2 caches, is usually the limiting factor for bus speeds in most Macintoshes. Be aware however, that most Apple motherboards designs are not guaranteed beyond 50mhz even with no L2 cache, but most of them seem to be able to do 55mhz or so with the PowerLogix cache. PCI cards, etc. can also be a limiting factor, as can extensions such as Now utilities, but are less common causes of problems at accelerated bus speeds in most systems. (Note: We hear the Now utilities requires a reinstall whenever the CPU speed is changed - so remove them prior to upgrading your Mac. If you must use them, reinstall them after all upgrades are done and the system has proven reliable). If you have questions about this procedure, feel free to contact me. Here's the routine: Set processor card to 4:1 ratio using this knob Insert card in Mac Set remote control bus speed to 50mhz to start Boot Mac Runs OK? Increase bus speed knob one setting Errors? Decrease bus speed knob one setting. Goto step 4, verify reliability in normal use. That's basically it folks. With the fine speed adjustments you can for the first time truly maximize the performance of any processor card upgradeable Mac using the Pro. And should you later upgrade your cache, you'll be glad you have the large range of adjustments as well. As I said in the opening, this card has no compromises.
Warranty:
As with all PowerLogix PowerBoost cards, this product carries a 30 day money back guarantee and a 3 year limited warranty. From my experience you will not want to return this card - ever. It's the best designed series of 604E cards I've seen - and I've tested all of the top name brands to date.
Base System Notes:
The base system used to test the PowerBoostTM was our standard PowerMac 8500, with 128megs of matched memory (60ns), standard built-in video with 4 megs Vram, running OS 7.6.1. Disk cache was 512k, Speed doubler 2 and LibMoto were active (Speed Doublers faster disk access was disabled). Quicktime 2.5 and Quickdraw 3d extensions were also enabled (as done in prev. testing). Cache Used : PowerLogix 1 meg RapidCache (p/n: RC1MB02) (in my system the standard RapidCache runs as fast a bus speed as the Ultra model, and costs less).
Benchmark Notes:
All tests were run using MacBench 4.0 . All graphics tests were run at 1024x768, thousands of colors , not the lower resolutions and color settings used by most of the magazine reviews. We feel our settings are more in tune with actual users. Consider this when evaluating the video scores.
PowerLogix PowerBoostTMPro 233 Specifics:
Selectable Bus speeds from 40mhz to 70mhz in 0.3mhz increments. Remote Control for easy adjustment of bus speeds. CPU/Bus ratios of 3:1., 3.5:1, 4:1, 5:1, 6:1.
PowerLogix PowerBoostTM Pro 200mhz CPU Upgrade MacBench 4.0 Scores (A stock 8500/120 with the same L2 cache is shown for comparison)

For a graph showing the stock 8500/120 (256k cache) scores - click Here For scores of other cards (Newer 225, etc.) we've tested - click Here Be sure to check the Main Menu on the Home Page for other reviews and more information on cache.
= Where to Buy = Visit PowerLogix's pricing and Order pages for more information. For the best deals on Accelerators and Cache for your Mac always check MacGurus! latest prices. Their price as of 8/21/97 was $584.99 !
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