Streaming a little less than 40 MBps with PXIe-8133 controller

[ChrisClark]

Hi,

I need to stream 40 MBps to disk, .tdms, on a NI PXIe-8133, quad i7 1.73 GHz from 10 DIO cards. I understand that 40 MBps is roughly the max of what the SATA drive will do. I'm getting at least 30 MBps. Is the 40 MBps limit assumption good?

I think I should have a dedicated drive for the data instead of streaming to the controller drive. RAID is surely overkill. Has anyone connected an external drive to a NI controller with the ExpressCard slot? Any other ideas? I think my producer consumer code is ok.

cc

[ShaunR]

Hi,

I need to stream 40 MBps to disk, .tdms, on a NI PXIe-8133, quad i7 1.73 GHz from 10 DIO cards. I understand that 40 MBps is roughly the max of what the SATA drive will do. I'm getting at least 30 MBps. Is the 40 MBps limit assumption good?

I think I should have a dedicated drive for the data instead of streaming to the controller drive. RAID is surely overkill. Has anyone connected an external drive to a NI controller with the ExpressCard slot? Any other ideas? I think my producer consumer code is ok.

cc

Depends on the drive.

SATA 1.5 theoritical max is 150 MB/s, SATA 2 300MB/s and SATA 3 is 600MB/s. I have a NAS box at home that easily does a sustained 60MB/sec over a 1Gb connection (with Jumbo frames).

NI PXI racks have pretty crappy hard drives as standard I would benchmark it with these

http://zone.ni.com/devzone/cda/epd/p/id/5348

.....then buy a decent one

[ChrisClark]

Ok, I'm lame, my file write subvi was writing two files in parallel and I forgot to set it to reentrant.

FYI I was able to get at least 80 MBps with one loop, 10 DAQ Reads and 1or 2 File writes in the same loop, binary or tdms.

We replaced the NI drive with a WD Scorpio Black, 7200 rpm. Forgot about the benchmark VIs, thanks.

cc

[Cat]

Be careful if you're filling the disk up -- it will get much slower towards the "inside". The last benchmark I did on a 1TB Seagate disk went from 85MB/s at the start to 45MB/s when the disk was full.

[patleb]

Hey!

The link above

NI PXI racks have pretty crappy hard drives as standard I would benchmark it with these
http://zone.ni.com/d...a/epd/p/id/5348

References code writen in LabVIEW 8.0. When I try this with LV 2012 it can't find the file I/O vi. Does this file I/O vi need to open the file in non-buffered mode? And if so what vi must be substituted?

Thanks

Also using a PXIe with windows 7, is the file i/o compatable.

[patleb]

OOPs! My bad, got it working.

[patleb]

I have a PXIe 8133 that tests about 88MBps for read and write speeds and a PXI 8106 that tests at about 33MBps