Speeds

[AdamB]

What I am using at home

Intel Pentium 4 2.6Ghz
1.5GB Ram
2 x PWLA8391G Intel PCI NIC's
80Gig drive

When I setup this box I was originally using some very cheap NIC interfaces and not seeing the speeds I should. I replaced the cheap NIC's with the PWLA8391G and I am getting the same exact speeds. On my speed tests both user and system cpu utilization doesn't go above 30%. My memory usage looks great.

My connection is 15 down and 5 up. I planned on changing that to 25/25 in the next few days but that will wait.

One thing I note that is a bit odd. When changing the interface speed from "auto" to "100MB Full Duplex" my speed tests get much better. Then after a bit they slow right back down. Then when I go from "100MB Full Duplex" back to "auto" it does the same thing. I am using untangle behind my Verizon Fios router.

[raditude]

When you say the CPU utilization doesnt go above 30%, are you getting the number 30 from the menu bar at the top? That is not a %, that is telling you that you have 30 processes waiting with a P4 (single processor). With a P4 you should not go above 1, or you have processes waiting.

[AdamB]

When you say the CPU utilization doesnt go above 30%, are you getting the number 30 from the menu bar at the top? That is not a %, that is telling you that you have 30 processes waiting with a P4 (single processor). With a P4 you should not go above 1, or you have processes waiting.

No that is by placing my mouse on that box and watching user utilization, I have also watched from TOP to.

[GeneralEclectic]

There's something going on in background that repeatedly sets TCP parameters on the NICs. I have no idea what's doing it, or why. It became apparent when I tested the size of the TCP receive window on the external interface and found that it was set to an unreasonably small fixed value, with auto scaling off. I manually increased it and sat back with a smug look on my face. Then, a few days later, I noticed that things had slowed down a bit again and just for fun, checked the receive window again. It was back at the original setting. Say what??

Rinse and repeat.

Since I had no idea what was causing this, I took the crude, ugly, brute-force approach and set a cron job to set the window back to auto scaling every half hour. Subsequent tests demonstrated that every once in a while it's set to the small fixed value, but then within a few minutes the cron job comes along and kicks it back to auto.

I'd like to get to the bottom of it because the size of that window definitely DOES affect the rate at which you can transfer information, especially from far-away sources. You will notice it even more as your external interface speed increases. You will definitely notice it on a 25Mbit/sec connection.

[dmorris]

One thing I note that is a bit odd. When changing the interface speed from "auto" to "100MB Full Duplex" my speed tests get much better. Then after a bit they slow right back down. Then when I go from "100MB Full Duplex" back to "auto" it does the same thing. I am using untangle behind my Verizon Fios router.

Try putting a switch between your modem and untangle (with nothing except those two plugged in). Does it make a difference?

There are times when ethernet auto-negotiation of speed messes things up.

[sky-knight]

Yeah we really need to figure out what is causing this. The knowledge may open the door for use of realtek and similar interfaces in a more realistic way. I have a similar unit, p4 single core, 2.0ghz machine, 1gb of ram, two Intel Pro100 cards I had laying around. One of them is HP branded, the other is Dell. I got 80mbit through it during testing.

So what's the difference between my unit and yours?

What internet equipment are you using? What switches? Have you checked your patch cables for kinks or other damage?

[AdamB]

Yeah we really need to figure out what is causing this. The knowledge may open the door for use of realtek and similar interfaces in a more realistic way. I have a similar unit, p4 single core, 2.0ghz machine, 1gb of ram, two Intel Pro100 cards I had laying around. One of them is HP branded, the other is Dell. I got 80mbit through it during testing.

So what's the difference between my unit and yours?

What internet equipment are you using? What switches? Have you checked your patch cables for kinks or other damage?

Well I did some more digging into this issue. I completely eliminated my router from the picture and am using Untangle as my router also. I am seeing the same results with this configuration also. When I am using just my normal router without Untangle I get 15/5 all day so i don't think its any of my cabling (Brand new cat6). My network speed is right on par though, no problems there. I have a Pentium 4 laying around in this chip set which I am going throw in for shits to see if there is any difference. Thanks for the input everyone!

[dmorris]

Is QoS enabled?

[AdamB]

Is QoS enabled?

Nope

[sephiroth_4]

Any update and did you disable auto negotiation?