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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: WeiXing3D on February 18, 2016, 05:20:35 PM

Title: New SCSI to Micro SD Interface Adapter
Post by: WeiXing3D on February 18, 2016, 05:20:35 PM
Would the Amigakit SCSI to Micro SD Interface Adapter work with an Amiga 3000 to use as main HDD?
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: tonyvdb on February 18, 2016, 05:59:12 PM
Will it work, yes but with a 2.5Mb/sec transfer speed it wont be any faster at loading thats for sure.
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: XDelusion on February 18, 2016, 06:37:18 PM
Get class 10 if you do...

Though I wonder why they don't make these that use USB sticks instead.
They have a longer life span and are generally faster than SD.
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: WeiXing3D on February 18, 2016, 08:10:30 PM
Slower than an old SCSI HDD?
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: tonyvdb on February 18, 2016, 08:25:09 PM
even the old SCSI interface was around 10mb/sec.
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: Oldsmobile_Mike on February 18, 2016, 08:26:27 PM
2.5Mb/sec is plenty for most general Amiga tasks.  What's the max speed of stock A3000 SCSI, anyway?
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: tonyvdb on February 18, 2016, 08:52:10 PM
It was equipped with a DMA SCSI II controller.
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: Oldsmobile_Mike on February 18, 2016, 09:16:24 PM
Quote from: tonyvdb;804223
It was equipped with a DMA SCSI II controller.

Yes, but that tells us nothing.  What is the max speed this controller is capable of?  I.e., if you say the card does 2.5MB/sec but the controller is only capable of 3MB/sec, it's not exactly creating much of a bottleneck, you know?

TL;DR.  I use a 2.5MB/sec media card reader with my A2000 and it works just fine.  Of course other people have 30MB/sec UW-SCSI controllers on their CSPPC boards and still complain about not enough speed.  It's all relative, and what you want to do with it.

I think the biggest bottleneck of that particular card though is that it's write speed is like only 128KB/sec, or something like that?  Someone else posted specs in the forum a month or so back...
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: tonyvdb on February 18, 2016, 09:44:24 PM
I found a couple references in other forums that people were getting 4.4mb/sec (actually kind of surprising its that slow) on a stock A3000 using SCSIbench
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: desantii on February 18, 2016, 10:39:58 PM
Sysinfo(not sure reliable) says 2.1 mb/s on my 3000
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: mechy on February 18, 2016, 11:11:14 PM
Quote from: tonyvdb;804228
I found a couple references in other forums that people were getting 4.4mb/sec (actually kind of surprising its that slow) on a stock A3000 using SCSIbench

A3000 scsi tops out around 5MB/s synchronous so that is pretty close to it.
Its pretty fast for 1988 standards.

scsi on the accelerator such as warp engine etc will yield near 10MB/s

speedgeeks hacks may speed up the a3000 scsi a bit.

You will likely need a faster cpu to get to the magic 5MB/s mark without hacks.
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: spudje on February 18, 2016, 11:41:16 PM
Thanks guys! This thread confirms my thinking. I have a FastATA in my A3000 and can get it to around 4,5 mbps in PIO3. So that's quicker than this SD2SCSI thing, which I first considered so I could free up a zorro slot, but not anymore.

PIO4 is unstable on my machine. From what I understand here I might even get PIO4 stable if I get a faster CF card (or potentially better IDE-CF adapter)? PIO 5 is not an option as it is not supported by any device, I'm told.
Title: Re: New SCSI to Micro SD Interface Adapter
Post by: matt3k on February 18, 2016, 11:58:35 PM
The fastest I ever got on the 3k SCSI is 4.4 m/s.  Which for it's day was real fast.  Boot times and usage at 4.4 or 24 m/s is not real noticable since file sizes on the Amiga are so small.  

My Cyberstorm SCSI yields about 24 m/s with my Acard SCSI to SATA converter on a SSD. To be honest, as I said not a big visual difference between the native scsi and the cyberstorm for IO in normal usage.

The 3K is an all around great box, the scsi is no exception with DMA transfers.

Never tried a Micro SD interface.  I went with SSD's and I haven't been disappointed.

SCSI is certainly much better than IDE from that era.  IDE killed the performance of my 4000, so I went with SCSI on the warp engine and never looked back.  IDE uses to much cpu for IO on the 4000, SCSI was always so elegant with IO in comparison.