Sonnet Presto 040 CPU Upgrade

Got an old Color Classic, LC, LC II that’s just too slow to keep using? Using an LC III, LC 520, or LC 550 that just doesn’t pack enough power? If so, Sonnet Technology had a solution in the Presto 040 accelerator, which can push these older Macs to Quadra level performance.

Sonnet Presto 040 for LC PDSAlthough discontinued, you may still be able to find some. If not, their newer, faster Presto Plus card is expected out in May.

The older Presto 040 came in two versions: a full 25 MHz 68040 with internal math coprocessor and a less expensive one with a 25 MHz 68LC040, which lacks the math coprocessor. The forthcoming Presto Plus will use either a 33 MHz 68040 or 68LC040, along with 32 MB of additional memory and an ethernet port.

How Fast Is It?

We bought a pair of these for the LC and LC II used by our oldest sons a little over a year ago. The included software allows installation of Mac OS 8 and 8.1, as well as access to 12 MB of memory in an LC II with two 4 MB SIMMs installed, overcoming the normal 10 MB limit. (The LC II has this configuration.)

This past week, one of my sons acquired a used Color Classic. It’s cute, but it’s also as slow as his LC II, so over the weekend we transplanted the Presto from his old LC II to the Color Classic, installed the Presto drivers, and ran a few benchmarks.

Using old-but-reliable Speedometer 4, we compared regular Color Classic (this one came with a 68882 math coprocessor) performance and accelerated performance. (For more details, read the benchmark report.)

Where the Color Classic provided comparable CPU performance to the Mac II, IIcx, and IIsi, the Presto card pushed it to the Quadra level, almost matching the 25 MHz 68040-based Centris or Quadra 660av. The overall boost in CPU performance was threefold.

Graphics performance doubled. Where it had been close to the Mac II and IIcx with Apple’s 8-bit video card, it now matches my Mac IIfx with 8•24GC video card. It still lags behind the performance of the video-optimized 660av, but video performance is very impressive.

The only drawback on the Color Classic is that we had to remove the extra VRAM for the Presto to work properly. This was not an issue with either the LC or LC II, but it does mean we can’t use 16-bit video on the Color Classic.

The Presto accelerator had no impact on hard drive performance, which should be expected. To improve that, you need a better hard drive.

In the math test, the Presto card with the FPU-less 68LC040 not only outperformed the 16 MHz 68882 FPU installed in this Color Classic – it turned in over twice the speed! While this is but a fraction (28%) of the performance of a full 68040 in a 660av, it is nonetheless impressive performance. It definitely moves the LC, LC II, or Color Classic past Mac IIfx performance.


Why am I reviewing a discontinued product you may not be able to buy?

Partly because we’re pretty excited to finally have a Color Classic in the house, and partly because Sonnet should be introducing an even faster card, the Presto Plus, in a few months.

We have had no compatibility problems with the Presto, other than the requirement to remove extra VRAM from the Color Classic. It takes a cute but poky computer and makes it comfortably fast. And, on the LC II, it breaks the 10 MB memory barrier hardwired into that computer’s chips.

This bodes well for the Presto Plus, as does experience with Sonnet’s Presto 040 card in eight Mac IIcis at work.

The new 33 MHz Presto Plus card should provide about one-third better performance than the old Presto, which ought to make it comparable to the 33 MHz Quadra 650. Beyond performance, it will add 32 MB of RAM to whatever amount of memory is already installed on your LC, LC II, Color Classic, LC 520, LC 550, etc.

Finally, recognizing that we’re moving beyond LocalTalk and that these models only have one expansion slot, the inclusion of ethernet will be a real blessing.

Whether the Presto Plus will be worth US$299 or US$399 (for the 68LC040 and 68040 models, respectively) remains to be seen.

Macworld Macintosh Secrets, 5th ed., puts the value of the LC at US$25, while searching the sites of dealers selling used Quadras shows you can probably buy a used Centris 650 or Quadra 650 for less than the cost of the Presto Plus. Of course, in both cases you’d need to add a $40 ethernet transceiver and probably spend $40-80 to boost total RAM to 32 MB or greater, so that has to be factored in.

Whether a used Presto or a new Presto Plus is a good deal depends on how satisfied you are with your current Mac. If your only complaint is that it’s too slow, an accelerator might be your best bet. If it’s too slow and doesn’t have enough RAM, the Presto Plus could be a perfect solution.

But if you’re also contemplating adding a larger hard drive, you might be better served by a newer used Mac, such as a Quadra or even early Power Mac.

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