p vs. i - the heck?

October 9, 2008 8:27 AM

IBM-Hardwre-FIlter - So it's a shot in the dark, but anyone in the know about IBM Power servers? Specifically differences between the P550 and i550 offerings? I've got a bit

So I am not the hardware guy at all around here, and know next to nothing about IBM server offerings... We are on aging P550 hardware that is EOL. My boss has asked me to figure out why we are looking at $120k+ servers instead of replacing them with the i-series which seem to baseline at $30k.
I've looked at IBM's site, but can't seem to determine, if it's just a software stack, or if it's something specifically hardware. I've got a call into sales, but I'd prefer to get a slightly less-IBM centric view on the major differences prior to talking to them...
For the record, we are an AIX/PowerPC shop, and we cannot change that

posted by niteHawk to computers & internet (5 comments total)

Wikipedia seems to think that the i and p series only differ in software and services offerings, and to eliminate the confusion, have merged things into a single line called Power Systems.
posted by zsazsa at 8:35 AM on October 9, 2008

If you are running AIX I don't think there's much of a hardware difference between the high-end (POWER-based) System i systems and the lower end P-series ones. There might be some artificially introduced limitations into what types of accessories you can install, though.

The biggest difference, and the reason for the separate lines (up until a few months ago), was marketing: the i-series was the descendant of the AS/400 line. It was (relatively) low-cost, and was sort of separate from the more AIX-centric product lines. I knew places that were AS/400 shops that had zero interest in the AIX machines, and AIX shops that wouldn't have known what to do with an AS/400 besides use it as a space heater...

Since you can now run AIX on either, the distinction seems pretty artificial, and apparently they realized that and have unified them. (I suspect to keep the high-end System i sales from cannibalizing the System p sales.)

It seems like IBM has basically done the job for you; now the only question is really picking which of the "Power Systems" you need based on capacity/features/etc.
posted by Kadin2048 at 9:00 AM on October 9, 2008

p == rs6k
i == as/400

what is your old system running, aix? os/400? i5/os?
(if it's a power5 as you mentioned, I would assume it's aix)

for what it's worth, the virtualization in i will let you run aix, linux, windows... but that may cost extra.
posted by dorian at 9:01 AM on October 9, 2008

If it's a question of performance between the two systems, your IBM rep should be able to provide price/performance numbers to help you decide. if you do need to grow, you're going to have more headroom with the P series.
posted by jrishel at 10:39 AM on October 9, 2008

Is there any chance that you mean to compare p-series vs x-series?

The "P"s are Power-based systems designed to run AIX (or Linux as an alternative).

The "X"s are IBM's range of x86 PC servers. They typically run Windows or Linux.

The "I" series are exactly the same as the "P" series but they run OS/400 instead of AIX.

Pricing for the P- and I- series is pretty similar from what I remember, but there's a big price difference with the X- series.

A single P-series box with a large number of Power6 CPUs is a hugely powerful server - but it is also very expensive (several million dollars for a system we looked at). For much less money, you can buy lots of cheaper X-series boxes and run them in parallel, which gives higher CPU, memory and I/O capacity than the single P-series box - but this depends entirely on your application and whether it can be run that way.
posted by standbythree at 11:10 AM on October 9, 2008