The equipment:
PowerMac G4/450
768MB RAM
ADTX K-Series RAID (
http://www.adtx.com/english/k-series.html)
Adaptec Ultra2 SCSI Card
Asante GigaNIX 1000TA NIC
Netgear GS508 8-port Gigabit Switch
CAT5e cabling
Mac OS X Server 10.2.1
The problem:
Network performance is WAY lower than expected. If you read my last post on the subject (included at the end of this message) you know what the theoretical performance should be. Unfortunately those numbers don't match my results.
The Results:
- Drive to drive copy on Dual 1GHz client Machine for
reference purposes:
- Time: 29 seconds or 20.2MBps
- Finder copy of 2 files totaling 585.8MB from a 7200RPM FireWire
drive on a Dual 1GHz PowerMac:
- Server: G4/450 - 768MB RAM
Time: 37 seconds or 15.8MBps
- Server: G4/450 - 1.5GB RAM
Time: 31 seconds or 18.9MBps
- Server: G4 Dual 1-GHz - 1GB RAM (this one to a machine running OS X Client using "personal file sharing" for reference)
Time: 29 seconds or 20.2MBps
- Dual finder copies of same 2 files. Same process as above, but from 2 different Dual 1GHz PowerMacs. Some of these test were done using two NIC cards (one client connected to each one separately), but I don't recall making a noticeable impact on the copy time.
- Server: G4/450 - 768MB RAM
Time: 75 seconds - 15.6MBps
- Server: G4/450 - 1.5GB RAM
Time: 59 seconds or 19.8MBps
- Server: G4 Dual 500 - 1.5GB RAM
Time: 45 seconds or 26MBps
- Final Cut Pro Tests using the G4/450 as server and
3 simultaneous video capture from 3 different clients:
- With 1.5GB RAM and 2 NICs on server - Worked perfectly.
(2 clients connected via one NIC, third client via second one)
- With 1.5GB RAM and 1 NIC on server - Dropped frames.
- With 768RAM and 2 NICs on server - Dropped frames.
- With 768RAM and 1 NIC on server - Dropped frames.
The Conclusions/Questions:
Seems to me that CPU performance and RAM play a much bigger part on the server performance than I anticipated. I'm still 10MBps away from what I anticipated, but I believe I'll be OK as long as I outfit the server with as much RAM as it can take. Anyone know of any table or test that can show me a graph of server-performance vs. CPU speed or amount of RAM? Any other way to increase my server/network performance otherwise?
Since my "reference" copy topped-off at 20MBps, I can attribute my single-file-copy performance on the transfer-speed limitation of the FireWire IDE drives....right?
There is a 4th computer in this whole equation that is yet to be tested by capturing video at the same time as the other 3. This computer is different in that it does not have a built-in Gigabit Ethernet port, but I'm starting to believe that might not be necessary after all. My theory is that since 100Mbps should be capable of 12.5MBps this machine should be capable of keeping up with the 3.7MBps needed for DV. I tested this machine capturing video to the server by itself and everything worked fine.
Am I right in assuming that since the server is connected via Gigabit Ethernet onto a Gigabit Switch my server bottleneck is gone? If all 4 clients were connected to the switch via 100Mbps Ethernet, does the switch take care of being able to deliver 400Mbps to the server (theoretical numbers, of course)?
----
Original message:
> I have a client who need a shared storage solution for 4 Final Cut Pro
> editing systems all running under OS X. Originally they wanted to go with a
> SAN (Storage Area Network) solution, but all the currently available
> solutions are strictly OS 9 for the time being. The client is not willing to
> go back to OS 9, so I had to get creative.
>
> From what I've been able to gather, if I have an OS X Server machine running
> on a PowerMac G4/450 with an Ultra160 SCSI RAID Level 5 storage system that
> is capable of 130 MB/second (the Medea RTR 320GB drives at
http://medea.com)
> I could easily achieve about 30 MB/second on a 'write' to that server. Part
> of this information comes from:
>
>
http://www.xlr8yourmac.com/feedback/..._vs_snap_.html
>
> So, since DV only requires roughly 3.7 MB/second...
>
>
http://www.insanely-great.com/infobank/firewirehd.html
>
> ...this means that 4 FCP stations should EASILY handle the worst case
> scenario of all 4 stations capturing video directly to the shared drive at
> the same time. Right? Am I missing anything here?