View Full Version : server speed & TCP/IP

01-27-2003, 09:09 PM
ok, this issue has been brought up a few times before, but lets see if we can get some answers, or maybe some better questions:

If I have a server, and my max throughput via tcp/ip to a client mac is, say, 5mb/sec, does it really matter if I have a screaming raid on that server?

I would think that all you need is smoking processors and a fast PCI to handle multiple IOs. And for storage low end IDE should do it. Am I mistaken?

I would like to see some benchmarks on TCP/IP thoughput with various configurations of hard drives, processors, etc.


01-27-2003, 10:28 PM
The limiting factor with TCP/IP is usually Ethernet controller chip speed. If your network hardware (PCI card, or motherboard Ethernet controller) is faster (10Mbps vs. 100Mbps vs 1000Mbps), your computer will not usually have trouble throwing data down the pipe.

Granted, a slow IDE drive cannot saturate a Gigabit Ethernet connection, but most people are not in that situation.

So let's assume you have a small LAN, with a mixture of old and new Macs. The old ones have built-in Ethernet that is capped at 10Mbps, the new one(s) have 10/100 controllers.
Assuming all machines have acceptable amounts of RAM, and PowerPC processors, the best thing you could do for your network is switch to faster 100Mbps controllers on the slow machines.
After that, you would upgrade drives to Fast SCSI, LVD, or 7200 rpm EIDE, to make sure your drives could keep up with the network.

Another little tweak would be to upgrade your cables themselves, esp. if your cable run distances are in the 100-ft range. You'd be surprised at the difference a quality Ethernet cable can make.

Bottom line: TCP/IP benchmarks are not as useful as you'd think, b/c processors and drive speed don't make as much difference as the I/O controller chips' speed.

01-28-2003, 08:29 AM
good points, but let me be more specific.

IF I have a 100T network, with cat 5e cable, gigabit G4s and a server, and the computers only use the network to copy files back and forth from the server (working locally, saving back when done), and the speeds max out at 5-10MB/s for copying, how fast does the server really need to be.

01-28-2003, 10:09 AM
IMHO: It really depends (primarily) on what you want your server to do and how many clients are in the mix. File serving a few large files to a few clients over some Ethernet flavour probably wont be much improved by RAID up the wazoo (yes, here improving Enet speed is the way to go) ... as long as you can saturate the connection with basic IDE speed. Nice Gig-Gig connections over a good switch can certainly tax a server ... but you'll probably be limited by the client side even if your server has RAID stripes. Here it would depend upon the number of clients ...
Biggest differences are in heavy-hitting database and web access that do a lot of disk I/O. A SCSI RAID or hardware IDE RAID (to some extent) will be justified here ...
The real use for RAID at the low-end is for redundancy in case of drive failure.
Anyone who sets up a server without RAID mirrors/failover is fooling themselves ... or they can afford the downtime and hell.

01-28-2003, 11:45 AM
i agree. I have an 0+1. I will be putting together a new server solution and am at a crossroad.

I will be getting a gig switch. currently have an 8+1.

the file server is just that, serves 4 clients, large directories of files. Basically, we copy all the scans local, do the color work/ retouching/whatever, and copy back when we are done. So we are talking 500MB- GB on average of copy, sometimes simultaneous.