[rescue] Some SCSI2SD Numbers

Eddie Cottongim eddie_cottongim at cox.net
Wed Nov 1 02:41:47 CDT 2017

Since we were discussing various SCSI replacements, I got some speed 
numbers for both the V5 and V5 SCSI2SD devices.

SPARCStation 20 built in SCSI controller - CDROM cable.
Patriot "Class 10" 32 GB SD Card
Linux (probably a 2.6ish kernel)
I tried a few file benchmarking tools, but didn't really like any of 
them and got tired of building them, so I stuck to sequential speeds 
with "dd".

The third number is the V6 in "turbo" mode, supposed to drive the SD 
card faster and perhaps push the SCSI timings.

Sequential reads
dd if=gcc-4.6.4.tar.bz2  bs=512 of=/dev/null
v5        72006076 bytes (72 MB) copied, 60.1136 seconds, 1.2 MB/s
v6        72006076 bytes (72 MB) copied, 14.6039 seconds, 4.9 MB/s
v6 6.1.1T    72006076 bytes (72 MB) copied, 14.231 seconds, 5.1 MB/s

dd if=curl.tar.gz   bs=4096 of=/dev/null
v5        59883520 bytes (60 MB) copied, 51.6644 seconds, 1.2 MB/s
v6        59883520 bytes (60 MB) copied, 10.0634 seconds, 6.0 MB/s
v6 6.1.1T    59883520 bytes (60 MB) copied, 9.96611 seconds, 6.0 MB/s

Sequential writes
dd if=/dev/zero bs=512 count=65536 of=testfile
v5        33554432 bytes (34 MB) copied, 18.3618 seconds, 1.8 MB/s
v6        33554432 bytes (34 MB) copied, 17.491 seconds, 1.9 MB/s
v6 6.1.1T    33554432 bytes (34 MB) copied, 15.1965 seconds, 2.2 MB/s

Its definitely worth using at least a Class 10 SD card. I also tried a 
Class 4 card, and it topped out at about 1.2 mb/sec read, 850 kb/sec 
write even on the V6.
The Class 10 card is supposed to do at least 10 mb/sec write, and at 
least that much (maybe much more) read. These numbers didn't come as 
close as I expected.
I saw some minor improvements with the latest V5 firmware (reflected above).

I hope these are interesting.

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