on vtools/68kmla

Accelerating the SE/30

When I got my SE/30 and got it running, I immediately declared it perfect and was intent on leaving it alone and simply using it as-is. However, and I would never admit it, I did feel that the standard 16MHz 68030 processor could perhaps do with a bit more power, as compared to my 68040 LC475 running the same System 7.5.3 it felt noticeably sluggish.

Now, back in the early to mid 1990s, a number of companies produced 'accelator' cards for various Macintoshes; there were offerings from DayStar and DiiMO amongst others. These had the potential to, as the name suggests, accelerate your Macintosh. The cards came with another, faster processor onboard which could take over from the standard CPU and as such, increase the machine's performance. However, the cards were expensive when new, and as time has passed have become harder and harder to find. Occasionally one will come up on eBay at a ludicrous price (often considerably more than the machine to which they'd be fitted) or maybe you'd stumble on a machine for sale which already had one fitted. I have seen a number of Macintosh SEs with DayStar cards fitted, but very few SE/30s with any sort of accelerator installed.

Finally, however, I actually managed to be at the right place at the right time. I wasn't aware until I found out about these, but a guy in Germany has been quietly reverse-engineering certain hard-to-find Macintosh PDS cards, and was proudly declaring that his reproduction DiiMO 030 card for SE/30 was working perfectly. He'd produced a handful of these and was offering them for sale, and I was in a position financially to be able to afford one. I'm not going to discuss price, but it was considerably less than I paid for the SE/30 itself, and this card came complete with a fully tested 68030 fitted.

So here it is. As you can see, like the original card, it has a passthrough port at the top of the card at an angle, so in theory you can plug in another card through it, for example an ethernet card. Unfortunately I don't have any more PDS cards so I can't test this, but it's a nice feature.

DiiMO 030

The card has a space for a FPU (68882), but it's not fitted. What's important here is that the 68030 on the card is the 50MHz variant, which is considerably more than the 16MHz that the SE/30 has as standard. Let's get it fitted.

DiiMO installed

Easy to fit, once the case back is removed, the PDS slot on the motherboard is clearly visible down the right hand side. There are two screw holes so you can secure the card to the chassis, but I suspect my chassis may not be entirely straight any more as they don't quite line up, so I didn't bother with the screws. Also note my 'insulated' SCSI2SD installation using the box it came in.

Let's get on to performance. Whilst I can tell you that it's made a huge difference to how the machine feels to use, the best way to show this in text is via numbers. So I ran MacBench 3 both with and without the card installed to show the difference.

Macbench info

On the right you can see the SE/30 in it's stock (without the card installed) configuration, and the middle shows with the card in. The only real difference here is the processor speed that jumps from 16MHz to 50 MHz.

Macbench graph

Now the fun bit. Here's the comparison graphs between the stock SE/30, the SE/30 with the DiiMO installed and working, and for a test just to see what happens; the DiiMO installed but extensions turned off. As you can see, on paper the DiiMO makes a huge difference. I can tell you that it feels faster, and the numbers here confirm that it's not just in my head, it is faster. Interestingly, without the extensions running (DiiMO has a control panel that enables it's caches), it makes a tiny amount of difference, but not massive.

There we go. I'll go and claim again that I'm now going to leave the SE/30 alone as it's now extra-perfect, but who knows what cards I'll find in the future. I'm currently using it for word processing (I'm typing this text on it right now), and it's such a joy to use. Would recommend.