Bottom Line enters the G3 CPU card market with the Railgun, the lowest cost ($699.99) 1 MB cache model available at the time of this review. Based on the PowerForce design, the Railgun is a 250 Mhz PowerPC G3/750 CPU with 1MB of backside cache running at 166 Mhz (1.5:1 ratio). They also supply a 2:1 CPU/Cache ratio extension for use with higher speed CPU settings, as like all PowerForce designs the card is adjustable for higher than rated CPU speeds. Results of my tests with the supplied sample card were very positive, and it ran fine with the PowerTower Pro 1MB motherboard cache dimm installed. This particular card ran reliably at speeds as high as 312/208 for a 24 hour burn-in period, making it a very good value for compared to other 1 MB cache size G3 cards.

As many of you already know, there are currently only two different G3 CPU card designs on the market, the Newer Technology cards with limited speed adjustments (now to be offered by Techworks as well) and the PowerLogix PowerForce design which offers a much wider range of speeds. The Railgun card is the latest offering in the PowerForce design cards and Bottom Line's first entry into the CPU card market. I'm impressed from what I've seen so far.

I rated the card using my standard categories as shown below:

1. BenchMark Performance: MacBench CPU scores are run at various speeds found to be reliable with this particular card, cache and system combination. BYTEMARK performance is also shown.
2. Applications Performance: How the card did in CPU intensive tests like Infini-D and Bryce 2. The Bryce 2 tests are about 5 minutes in duration typically, but the Infini-D test takes approximately one hour complete and should show meaningful deltas in performance (rather than a 3 second filter operation in Photoshop). Standard sample files are used, and the applications are using their default RAM allocations. It's not perfect, but considering my current review backlog and time constraints it's the best I can do at the current time :-).
3. Software Controls: Ease of use and features of the supplied software controls.
4. Documentation: How clear and complete the installation and setup instructions are in the supplied manual.
5. Specifications: Features and details on the hardware design.
6. Price/Performance: Overall value rating. Covered in the summary.

For this review the ATI XClaim VR video card was installed in the top slot. To remain consistent with my other CPU card reviews, screen resolution was set to 1024x768, thousands colors.

The L2 Cache dimm of the PowerTower Pro did not have to be removed, all tests were done with the motherboard cache installed. However this may vary with other models and depending on your Mac. In the case of Apple Macs - I'd highly recommend removing it as the 256K caches they used were most often too slow to be reliable with a G3 CPU card. I'd estimate 90% of G3 upgrade problems are caused by L2 cache dimms and/or too high a bus speed setting.

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