Practical Gigabit Limitations

[isaacmacdonald]

I'm thinking of putting a gigabit card into an old proliant p200x2 server. Is there a chance that I'll be able to get decent bandwidth on that, or do I need substantially more cpu power to get tangible returns? (I'm thinking of just doing a crossover to my main workstation, using gigabit to make the proliant a file server)

Alternatively, I have a p3 500, but it's got a crappy 32bit pci bus and no scsi harddrives/controller. What do you think?

 

[skyking]

the hard drive access will be your bottleneck, not processor speed.

 

[cmetz]

If you think of gigabit as "greater than 100Mb/s", in general your expectations will be more reasonably set.

Still, neither of your boxes are likely to be able to move much more than 100Mb/s. Certainly not doing anything real-world. So I'd say don't bother.

 

[isaacmacdonald]

in which case, I should be good to go right? The proliant has a raid 5 configuration with 5 scsi2 7200 rpm drives...

 

[isaacmacdonald]

you don't think either will be able to exceed 12MB/sec? I don't get it... why not?

 

[alrox]

raid 5 on software raid/entry-mid level raid cards is downright slow. Benchmark the HD's before you invest any $$ into gigabit. What is your current network utilization on 100megabit now?

 

[isaacmacdonald]

hmm... yeah, I prob should bench them first. Nonetheless, it's certainly not a software raid card. It has the optional ram attatched and the card itself is like 2 feet long.

My whole plan was to buy two cheapo gigabit cards and run a crossover between my workstation and the proliant. There's another network, but I don't want to buy a gigabit switch (too pricey) so I figured I'd just keep two ethernet cards in the workstation. I assume this would remove the 100mb bottleneck and make the proliant the weakest link (I'm assuming 250mb/sec would be feasible).

 

[spidey07]

You could try it.

but at the processor speeds and slow drives/controllers your using you'll have a hard time sustaining 100 Mb, let alone 1000.

-edit- what I'm really saying is your network card isn't the bottle neck.

 

[isaacmacdonald]

well it seems like you're probably right, about the ol' proliant at least. It didn't weather the winter in the garage all that well and 1 scsi drive just didn't work, while the other indicates it's almost about to bite the dust. Suprisingly the biggest issue is latency. Stupid drives keep spinning up and down (maybe sad that the raid array is all in the toilet) and sisoft benchs them at 13M/sec (a far cry from the 50MB/sec claimed in the manual).

I'm sure most of that is based on only having 3 of 5 drives functional, but I kinda doubt it's worth trying to revive or replace them.

On the plus side, my p3 500 with an old maxtor 40gig/5400 benched a respectable 24MB/sec. Given its relative silence (compared to the 6x120mm fans in the proliant) I'm seriously considering using it as a little mp3/storage server. Might just say screw the gigabit stuff though.

 

[cmetz]

I would suggest trying it with 10/100 boards you have first, and only messing with gig if you can determine that the network is actually >90% utilization. If you're buying new boards anyway, though, the Intel Pro/1000MT is $46 at Newegg -- it's cheap enough.

 

[isaacmacdonald]

bizaa. HD benches @ about 24MB/sec, cpu utilization is less than 25% (on p3), yet the best transfer I can get is 67% utilization (writing to p3) and about 56% writing to my workstation. The fact that writing to p3 is faster seems pretty weird to me. My workstation (p4 2.53 w/ 2x wd1200jb) benches far higher than the p3.

Maybe the network adapters suck? got a PEV integrated on workstation + realtek on p3.

Incidentally, is there an alternative to tcp-ip protocol? Somthing I can use on my home network that has less overhead?