SCSI 2 SD Version 6 Card 2020 Rev C working !

[Rob Blessin Black Hole]

Hello NeXT Community: I took the plunge and have the SCSI2Sd Version 6 card working 2020 Rev C , the ealier vesion were always problematic ..... this is in process so I'm not sure of stability.

I also just ordered some exterme pro 16Gb SD Cards 170Mbs which ought to be interesting to check against the 95Mbs cards .

I prefer the Version 5.2 Cards becaue of proven stability but the version 6 cards provide direct access to the card , I'm tinkering .....    Best Regards Rob Blessin

[mgtremaine]

Curious to see if you can benchmark a difference. I think I read that the bus to the SDCard interface maxed out at 20/Mbs. But I could be wrong.

-Mike

[spitfire]

I'm not sure how much benefit there would be for faster cards. The NCR 53C90 and 53C90A
used in the next are SCSI-1. The 53C90 was PIO only, without DMA. The later 53C90A rectified this and added DMA.

So with SCSI-1 the absolute maximum speed we can see is 5MByte/sec. But with a 53C90 (PIO) I doubt we'd get that. 53C90A (DMA), probably. But you're still capped at 5MByte, etc.

I wonder if there are any faster drop in replacements for the NCR chip? Fast-20 SCSI can do 20mbyte a sec which would be lovely.

[spitfire]

Just be clear, I'm not against testing. Absolutely you should benchmark everything you can.
Then change one variable, and test everything again.

[milanojess]

Looking forward on the result and stability of v6 as well!

[rooprob]

TIL the 53C90A in my NextStation Turbo is a SCSI-1.

I thought it was SCSI-2, which was how I had enabled that on my SCSI2SD v5.

I've never been that happy with the performance, mostly latency, even with a fast Samsung SD Card.
I was playing around with it today and found I could get between 1MB and 3MB out of it with most of the options now disabled. Feels better (latency) so it will do me.

I only enable Parity and DisableGlitchFilter.
Everything else is off.