eSata speed difference on G-RAIDS?

[Steve Modica]

I wouldn’t worry about things like this. Those are little configuration file touches. There’s nothing going on there.

I’d run this while your benchmark app is running. Then you’ll see some much larger time numbers and you can compare.

Steve Modica
CTO, Small Tree Communications

[Thomas Morter-laing]

Thanks very much, that makes sense. Are you saying I should compare with the numbers at my other imac and GRAID?

I’m getting numbers like
10024 501 1998 W 318081566 1048576 DiskSpeedTest ??/G-RAID 001/DiskSpeedTestTemp
and
10155 501 1998 R 317863890 286720 DiskSpeedTest ??/G-RAID 001/DiskSpeedTestTemp

Do you think theyre normal looking isn?

Tom Morter-Laing
Twitter- @TomTheEditor
_________________________________________________

iMac 27″ intel i7 3.4GHz, 12GB RAM, ATI HD 6970M [2GB GDDR5], 3x G-Tech G-RAID (0) 2TB over Thunderbolt via Sonnet Echo Pro ExpressCard/34 Thunderbolt adapter and Tempo™ SATA Pro 6Gb ExpressCard/34.

[Steve Modica]

[Thomas Morter-Laing] “10024 501 1998 W 318081566 1048576 DiskSpeedTest ??/G-RAID 001/DiskSpeedTestTemp
and
10155 501 1998 R 317863890 286720 DiskSpeedTest ??/G-RAID 001/DiskSpeedTestTemp”

This says that it takes about 10msec for an IO. These IOs are roughly 1MB and 256K. 10msec for 1MB isn’t fast enough for uncompressed stuff, but it’s OK for Pro Res. If all the IOs are 1MB, that’s not usually very efficient (although it depends on your raids stripe size). We aim for 4MB.

Obviously one or two IOs isn’t going to break a stream (the app reads ahead), but if you see a lot of smaller IOs that take 10msec, that’s not a good thing. As you might imagine, doing a 4MB IO isn’t going to take 40msec. It might finish in 16msec. That would mean roughly 4msec per MB instead of 10msec.

Steve

Steve Modica
CTO, Small Tree Communications

[Thomas Morter-laing]

Well its a G-RAID, so 2 1TB drives hardware striped together- isnt that about what I should expect from that level of hardware over esata? What would you suggest I do?

Tom Morter-Laing
Twitter- @TomTheEditor
_________________________________________________

iMac 27″ intel i7 3.4GHz, 12GB RAM, ATI HD 6970M [2GB GDDR5], 3x G-Tech G-RAID (0) 2TB over Thunderbolt via Sonnet Echo Pro ExpressCard/34 Thunderbolt adapter and Tempo™ SATA Pro 6Gb ExpressCard/34.

[Steve Modica]

That’s about right. I would expect 2 drives striped to max out at around 100MB/sec (minus overhead for parity and the bus). So 1MB in 10msec sounds right to me.

Steve Modica
CTO, Small Tree Communications