AT&T 3b2 vs SCSI2SD drive replacement

Josh Dersch derschjo at
Wed Jun 1 15:53:10 CDT 2016

On Wed, Jun 1, 2016 at 1:08 PM, Swift Griggs <swiftgriggs at> wrote:

> On Wed, 1 Jun 2016, Pete Turnbull wrote:
> > Not so slow that it's awful on an Indy (apart maybe from booting), but
> > noticeably slower than people expect on faster machines.  The ACARD ones
> > seem to be faster.  Perhaps it won't matter for older machines.
> The Acard device is @250 bucks. It appears that the SCSI2SD is $50-$100
> depending who who is selling. I can tell you that the ACARD device is much
> faster than the Seagate Barracuda drive I was using before in my R5k Indy.
> I did a test using several benchmarks. There wasn't a single metric which
> was better on the old drive. The biggest change was in latency. It made a
> serious difference using the machine as a desktop. It also worked
> outstandingly well as a video capture destination - no dropped frames. I
> use a 2.5" 128G Samsung 850 Pro SATA disk internally inside the 3.5"
> device.
> -Swift
The advantages of the SCSI2SD over the ACard are as follows:

1) It's open-source (hardware and firmware and software)
2) The developer is extremely responsive to bug reports / feature requests
3) It's very flexible -- you can make it look like any drive you want to
(important for machines that expect to see only certain drives), it
supports oddball sector sizes (for your lisp machines and AS/400s), it can
support multiple drives on a single board, pretend to be a CD-ROM, etc,
etc, etc.
4) It's considerably cheaper.

It's probably slower than a real drive some instances, but in equally as
many instances that you're going to use something like this, the host
machine isn't going to reach peak throughput anyway.

- Josh

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