TCP overhead, alternative protocols???

[isaacmacdonald]

I've officially run out of slots and cooling capacity for my harddrives. I've decided to shift 3 of them over to an older p3 that's just sitting around. Right now I'm just using a crossover cable to connect the p3 to an extra ethernet card on my main rig. Anyway, given my setup, I'm wondering whether there's a protocol that involves less overhead than tcp that I can use to share files, or sort of use my p3 as a slowww external harddrive.

Alternatively I was considering using firewire to network the two computers, but I'm not sure that, aside from additional bandwidth, the actual cpu overhead will be reduced.

any thoughts?

 

[Smilin]

Netbeui is what you are looking for. It's about as lightweight as protocols get plus is has the added security of being non-routable. It's the perfect protocol for file-sharing on lan's. All MS OSes have this protocol but with xp it doesn't come by default - you'll find it on the xp cd.

That said - it ain't going to be much better. You'll get an extra couple percent transfer rate tops. All protocols from noisy-assed ipx/spx to netbeui don't have much variation between them.

 

[carolinaviking]

smilin' is right!

 

[FoBoT]

you would get better speed running 1000TX between the two than switching protocols

 

[isaacmacdonald]

actually, I'm not really concerned with bandwidth, It's more about cpu utilization. I know that there's some overhead used for decoding/encoding tcp packets. Are any other protocols lighter on the utilization front?

 

[ScottMac]

Netbeui/NETBIOS is almost as bad as Appletalk.....among the "chattiest" of protocols and a great waster of bandwidth (Many broadcasts).

TCP/IP is about as slim as your gonna get.

Check around for tweaks to improve the TCP/IP overhead (MTU, etc)

Good Luck

Scott

 

[Buddha Bart]

I know that there's some overhead used for decoding/encoding tcp packets

Assuming you don't have a 486, this is a non-issue.

bart

 

[spidey07]

hey budda!

Intel and 3com actually have cards out that off load the TCP processing to a specialty processor on the NIC.

Believe it or not all the math involved in TCP can get intensive, esecially at 100 Mbs and higher for even today's processors.

 

[cmetz]

Most gigabit Ethernet boards worth anything support TCP checksum offload and also support jumbo frames and interrupt coalescing and have generally better bus interfaces than many low end 10/100 chips (there are good 10/100 chips out there, but your $5 NICs aren't using them!). An Intel Pro/1000MT is $41 from Newegg and has these features and good performance. And if you have reasonably recent PCs, you can get two gig boards and get >100Mb/s TCP performance. (two of the Intel boards are cheap enough, at $82 total, and just connect them with a normal STRAIGHT Ethernet cable -- 1000BaseT is auto-crossover and a 10/100 crossover cable that doesn't cross the unused pairs won't work right) Avoid the really cheap gig boards based on the Nat. Semi. chip.

TCP does introduce some extra overhead, yes. But modern OSs are heavily optimized for TCP common case performance to the point where "lower overhead" protocols may in fact run slower in practice. If your application is to just use the other disks as offline or warm storage and copy things back and forth, TCP has the right qualities for you. If you want to use them as a real filesystem, then TCP might not be the right answer -- but if you're running Windows (which I'm assuming), then remote filesystem performance is just never gonna be very good anyway.

Why don't you get a two-drive external Firewire IDE (I'm assuming you're using IDE) enclosure and a Firewire adapter and use that for some drives? It would sure seem to me that it's likely to be a lot faster, you get the convenience of a local disk (though a bit slower than direct IDE), and not all too expensive a move (maybe $100 total?). Or why not get a serial ATA adapter with the PATA<->SATA dongles (I think Promise makes a 4-port ATA RAID with 4 dongle retail kit that's like $120 at Newegg) and run the SATA cables to an external enclosure (it'll be kinda a kluge, but best performance of all and again not too expensive). If the problem you're really trying to solve is to get these disks outside your case but otherwise you really want to use them on your main PC, you should probably be using a disk-oriented solution and not a networking solution, as you'll get better performance for your $$ investment.

 

[Smilin]

I believe those NICs from Intel and 3com only offload processing for IPsec which is a monster on your CPU. They don't do any other AMP as far as I know. Netbeui is only chatty because of Netbios name resolution which it does by broadcast as a default. If you are using Netbios with any other protocol (like tcp/ip) it's going to be just as chatty.

This is all kindof a moot discussion. There are plenty of other bottlenecks to deal with besides protocol overhead that will make more of a difference. Kicking both nics over to full duplex for instance would make a much bigger difference.