LC III & LC 520/550 PDS slot compatibility

[Phipli]

Yes, they are connected.

Then your FPU is running at 50MHz, assuming the CPU is.

Not certain how it does its checks, but have a look at TattleTech and see what, if anything it says. Otherwise, just take it as given.

An upgrade card in a slower machine is rarely up to speed with a machine natively clocked at that speed. The closest you get tends to be upgrades that have RAM on board.

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macintoshgarden.org

 

[jasa1063]

Here is a comparison between the LC III with the Interware Booster and the stock configuration with a FPU using SpeedOMeter v3.23. This is running on System 7.1 w/Update 3.0 & QuickSANE v2.2

 

[Phipli]

Here is a comparison between the LC III with the Interware Booster and the stock configuration with a FPU using SpeedOMeter v3.23. This is running on System 7.1 w/Update 3.0 & QuickSANE v2.2

Hum. I'm going to suggest you unplug the logic board FPU and try again with the upgrade. Just out of curiosity.

 

[jasa1063]

Hum. I'm going to suggest you unplug the logic board FPU and try again with the upgrade. Just out of curiosity.

I already tried that and the results with the Interware Booster 030 were the same.

 

[zigzagjoe]

Concur with @Phipli that FPU is running at 50mhz. If you really want to put this to bed, remove the FPU from the booster card and try again. On the SE30 version it is optional and will automatically use the LB FPU (if present) when no FPU is installed. You should see a reduction in the FPU results, though it will still be better than stock as reported by Speedometer.

Norton System Info does a much better job of reporting raw FPU performance with less impact from CPU performance changes, though some FPU sub-tests are more affected than others.

 

[jasa1063]

Concur with @Phipli that FPU is running at 50mhz. If you really want to put this to bed, remove the FPU from the booster card and try again. On the SE30 version it is optional and will automatically use the LB FPU (if present) when no FPU is installed. You should see a reduction in the FPU results, though it will still be better than stock as reported by Speedometer.

Norton System Info does a much better job of reporting raw FPU performance with less impact from CPU performance changes, though some FPU sub-tests are more affected than others.

I have tried all the above and I am satisfied the the FPU is running @50MHz after all the testing and thankful for everyone's input here. I am certainly not going to loose any sleep over it

Thanks!

 

[jasa1063]

I've been wondering if someone would pick that up.

It is a close cousin to the SE/30 design I recently cloned, which means it runs at a multiple of the LB clock. Presumably 2x, for 50mhz in a system that was originally 25mhz. If your system clock is 33mhz, this card will not work. I think the guy was assuming that 30-LC5250F means for 520 and 550, however, the last 50 is the accelerator CPU MHZ rather than model and F refers to the presence of the FPU.

I'll be curious if booting from a floppy works with this accelerator, the SE/30 design had special logic to deal with that but it looks like the analogous GAL for this card is not present. Possibly not needed.

I tested a System 7.5.3 boot floppy and it works just fine with the accelerator installed.

 

[jasa1063]

Here are the benchmark results for Norton Utilities SI v3.5.3. It definitely shows the FPU is running faster than the 33MHz I originally thought.

 

[zigzagjoe]

I tested a System 7.5.3 boot floppy and it works just fine with the accelerator installed.

Figured as much - I can't imagine they'd ship this version being unable to do so where they addressed it on others. The LCIII must just not be timing sensitive in the same ways the earlier machines are.

Here are the benchmark results for Norton Utilities SI v3.5.3. It definitely shows the FPU is running faster than the 33MHz I originally thought.

Yeah, that's more along what I would expect to see.

 

[Phipli]

Here are the benchmark results for Norton Utilities SI v3.5.3. It definitely shows the FPU is running faster than the 33MHz I originally thought.

If you use an older version of System Info, it will be baselined against the Q700 and give nicer numbers for comparison.

 

[jasa1063]

If you use an older version of System Info, it will be baselined against the Q700 and give nicer numbers for comparison.

Thanks, I will give that a try.