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Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

 
Chris_404
New Member

4104GL Gigabit to 100Mb Performance Painfully Slow

I'm experiencing some major performance problems with a new 4104 ProCurve switch and was wondering if anyone else is having the same issues.

My 4104 has two 10/100/1000 20-port modules (J4908A). I've got one server, an Apple XServe, and several desktops which are a mixture of Macintosh and Windows machines. The server is connected to the switch at 1000Mb. Some of the desktps are 1000Mb and some are 100Mb.

When transfering data between the 1000Mb desktops and the server, in either direction, the transfer speed is normal (around 30-40 MB/s). When transfering data from a 100Mb desktop to the server, the transfer speed is normal (around 10 MB/s). However, when transfering data from the server to a 100Mb desktop, the transfer speed drops to about 1 MB/s.

I've tried the usual suspects, cabling, forcing duplex & speed, disabling LACP (which is known to cause problems with some Macintoshes). None of these have made a difference.

I've talked to tech support and they seem to think that it has something to do with the switch having to subdivide frames from the 1000Mb server down to the 100Mb client. They're looking into that now. However, at a separate location I have a 4108 with a similar setup. 1000Mb servers and a mixture of 1000Mb and 100Mb clients. The downstream transfer speed to the 100Mb clients in that facility is normal. The major difference is the modules that are installed in the 4108. In that switch the 1000Mb computers are all connected to 6-port 100/1000 modules (J4863A) and the 100Mb computers are all connected to 24-port 10/100 modules (J4862B).

That makes me wonder if the newer 10/100/1000 modules have some sort of issue that affects 1000-->100Mb transfers.

Anyone have a similar setup with similar results.

Thanks
20 REPLIES 20
SCOOTER
Esteemed Contributor

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

Hi chris,

Interesting, i've seen problems like this before but they were more or less fixed like you say with forcing speed-duplex and the LACP story.

I don't have the J4908A module so I cannot test anything (G5's, G4's and G3's here). I was thinking of expanding but I'll wait untill this problem is solved.

What did tech-support mean with "subdivide" the frames between the 1000Mb and 100Mb connections? And another question, are you in the US or Europe?

Regards,

SCOOTER
Chris McFarling
Advisor

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

"subdivide" was inaccurate on my part. It was actually a buffer issue that they were refering to I believe. They were thinking that maybe a buffer was not behaving correctly when transmitting from a 1000Mb device to a 100Mb device.

I'm in the U.S.
Marc Villeneuve_1
Regular Advisor

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

Hi.
HP should asked you before, but did you check for firmware update? In most case, It solve lot of trouble!

And look if you have the latest driver on the PC for NIC.

Marc
SCOOTER
Esteemed Contributor

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

@Mark

Sorry but this will not be solved by upgrading the firmware or driver of the NIC.

Trust me, been there done that.

SCOOTER
SCOOTER
Esteemed Contributor

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

@Chris,

Ah, thanks for the answer this is starting to make sence to me now. So this could be a hardware limitation? Did they tell you anything about a new revision of the module with lager capacity or would it be possible to increase the buffer softwarewise?

Regards,

SCOOTER
Chris McFarling
Advisor

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

Firmware is the latest rev.

Since last posting, this issue has been escalated to the engineering level at HP. Apparently someone else submitted a similar case about the same time as me regarding a different switch (I think they told me it was a 2800)

So there appears to be a definite problem. I haven't gotten any details yet, but I'm hoping some info will come in days instead of weeks.
Chris_404
New Member

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

I talked to HP today. It turns out the J4908A has a confirmed problem related to buffering 1000->100 Mb transfers. The 2800 also has a similar issue. They were able to ceate a software fix for the 2800. The J4908A however, would require too much time, resources, etc to correct this problem right away. If they end up rewriting a bunch of code in the future then they will most likely fix it at that point. Until then the problem remains.

The best workaround is to employ a 10/100 (J4862B) module and plug all 10/100 devices into it. Plug all 1000Mb devices into the J4908A. The problem apparently does not appear when doing 1000->100 Mb transfers as long as they're from the J4908A to the J4862B, it's an intra-module problem.
Olavi Vaino
New Member

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

Having similar problems with procurve 4108gl (one J4908A module installed).
Has HP issued some kind of official statement regarding this problem? I searched knowledge base but didn't find any.
Is it sure that problem does not appear when connecting gbit nics to J4908A and 100 mbit nics to J4862B?
Chris McFarling
Advisor

Re: 4104GL Gigabit to 100Mb Performance Painfully Slow

I'm not sure if they've issued an official statement or not, probably not though.

So far performance has been as expected with the combination of the J4908A and J4862B modules.

On a side note, HP had to send me three J4862B modules before I got one that actually worked. The first two would "disconnect" from the backplane unexpectedly.

I would try to get them to send you a J4862B free of charge. If they have to that enough times, they'll just fix the problem altogether I'd imagine.