Upgrade old N4000 to what?

[Steve Lewis]

Could I please have some opinions on the possibility of upgrading one of the oldest N4000s (4x360Mhz, 4Gb RAM). This old server cannot shift the volume of work required any more.

Our initial thoughts are for a new rp4440, 4cpus at 1Ghz, 8Gb RAM. The other option is an rp5400 with 875Mhz PA8700+s.

Question 1:
Does anyone have any real-world info on the 1Ghz PA8800s dual-core versus the 875Mhz PA8700+ ? Does the reduced on-chip cache slow the 8800s down to roughly the same speed?

Question 2:
The other potential issue is the reduced number of i/o slots. Previously we had SCSI cables galore, whereas now I am thinking of 2x2Gbit fibre and a switch or two.

But I am having difficulty pursuading the old-school management and crusty sysadmins that anything other than direct attached storage is going to give performance and reliability. What they dont know they dont trust. Any arguments for or against? Performance / expandibility? Its new to me too.

We run Informix which has only just been ported to Itanium2 native, so that technology step is still over a year away for our conversative organisation.

[Nigel Wright_2 · Accepted solution]

Steve

We have just sold a number of the 3440 and 4440 systems to customers. They look to be much better value than the 5470s. With the 4440 you can get 8CPUs and 64GB of memory in an entry level box. Another point to note is that HP have standardised on the rp4440/rx4640 footprint with the PA-RISC and Itanium boxes. They both use the zx-1 chipset so if you want to change to Itanium in the future it is a cpu swap. The 5470 appears to be reaching the end of its life in HPs plans.

We haven't got any performance stats back yet but on paper they look fast.

They are both planning to use them with fibre attached SAN storage. If you need any positive feedback on SAN storage I have some very happy customers who have made the switch. I am sure they can share their views with you.

Hope this helps.

best regards

Nigel Wright

[Joshua Scott]

Steve,

Your current server has a TPM rating of 24,200

The rp5470 w/ (4) 875MHz is at 54,600
The rp4440 w/ (4) 1GHz is at 98,000

If you look at raw CPU performance, I believe that the 32MB of shared secondary cache on the PA8800 makes up for the 768K reduction from the PA8700 chips:

rp5470 (2x 750MHz)
SPECfp2000_rate: 10.2
SPECint2000_rate: 11.8

rp3440 (2x 1GHz)
SPECfp2000_rate: 17.7
SPECint2000_rate: 17.9

so a 33% increase in CPU speed results in a 73% increase in floting point and a 51% increase in integer Benchmarks.

Josh

[A. Clay Stephenson]

Before you ask questions 1) and 2), it would be wise to ask and answer question 0): "Where are my current bottlenecks?" You would look really dumb, if after upgrading to blazingly fast CPU's and disks, you still had poor performance. You might find that your best efforts should be directed towards software. I have seen many, many cases where adding a single index outdid all the hardware/OS Tuning/Database Tuning by a factor of 10.

What might have really happened to your performance is that the data has grown to sizes where algorithms which were once adequate no longer are.

[Steve Lewis]

Thank you all for your well researched, experienced and intelligent answers.