As title.

Thanks.

If I understand correctly, load average doesn't really work that way.

Load Average explains the stress your processor is under. A load average of 1.00 means maximum efficient usage - anything over that means some processes are having to wait to be executed. If it's a short burst it's probably no big deal. But if all three of your load averages show a consistent value over 1.00 it's time for concern.

To answer your question, I don't think there's an easy way to say what the load average on one server would equal on a different server. It's more or less equilavent to comparing processor usage percentages between two servers.

There may be others who can give better advice, but as far as I know, the only way to know is to stress test the new server. If you are wondering what server to purchase/lease, perhaps you can do some research to see other's results. Perhaps others on the board have experience. But I think you will need to provide different information - as I understand it a load average of 2.5 is pretty meaningless in itself. If you can, please post more information about what type of apps you are running, and if you're looking to upgrade, some specs on the current server for comparison.

Sorry I can't be more help.

:) Another much shorter way to answer your question would have been:

If you're running a 1GB machine with 512MB and your load average is consistently 2.5, then by definition your server is *not* really able to handle the load efficiently. It will work of course, but it is experiencing stress and is slowing responses.

How do you find the load average?

It's easy, just type "uptime" on your linux machine. The last three numbers (the decimals) are your load average, and represent the load over the last 1, 5, and 15 minutes, respectively.

That's why a large first number but small second or third numbers is not such a big deal - it would mean that something is running right now that is stressing the processor, but it also means that overall the system is fine.

What you want to look at is the second or third numbers.

You can also run "top" which shows the load average, as well as a list of processes and an easier to understand "Current Processor Usage" percentage, as well as showing exactly which processes are the ones slowing you down.

Hope that helps you!

Thanks Getweb

You are a regular fountain of knowledge.

This is what I got so would you say this is a good way of "kicking the tires" when you get an account? BTW I'm on shared.

5:35am up 78 days, 20:08, 1 user, load average: 0.13, 0.16, 0.17

Thanks for the compliment purplemokey. I've been doing this 18 months now so I'm starting to understand it :) I don't know if Chicken remembers but I was active for awhile on another board he was moderator for when I got GetWebspace started. To be honest, I left the boards for over a year because I was still building a business and the temptation to "fish for customers" was too great. But I miss the community and maybe I can start providing unbiased help now.

Anyway, in my experience 0.16 means you're getting some steady traffic but your server is not at all affected by the load. My servers are pretty consistently the same thing, between 0.10 and 0.20. We started to see 0.60 from a large customer's dynamic site traffic (50GB+/month) before we left Raq3's in favor of PIII/800s.

Now that I think about it, I'm not sure if I'm a font of knowledge, or just like to hear myself type a little too much. Comes from too few support emails to answer I guess, a problem I really don't mind :)

With about 400 visitors online at the same time, the load average is between 2.5 and 3.0. Is there a way to reduce it? Add more memory? Use a faster CPU?

Thanks.

If you've already got a 1GHz machine with 512MB RAM and a load like 2.5, you might want to look into splitting the load across two servers, if you have that kind of cash. You can try upping the RAM otherwise.

A good way to tell is to run "top" and see what your memory usage is. You'll see Mem and Swap at the top of the display. Watch your "free" on your Mem and the "used" on the Swap. If you have a good amount of free Mem and your Swap is zero, then more RAM won't help you. But if you have a lot of Swap, adding RAM will probably help you out a lot!

Be sure you're running as efficiently as possible, if you have the ability to make code changes. With 400 users online, any small change in code that improves efficiency could make a big difference overall. Plus it's cheaper :)

Originally posted by ebird
As title.

Thanks.

You do not provide enough information to give a clear answer.

A general rule of thumb is, that your load average should not be continually higher than the number of CPUs in your server.

If you have 4 CPUs in your server, and your load average is 2.5 -- then you should be quite okay.

If you only have 1 CPU in your server -- you might want to take a look at either optimizing your current software configuration, upgrading to better hardware or load balancing between several servers.

You really shouldnt notice very much if any delay in server speed from the web side of things on a server with a load of 2.5.

-Brendan