Greetings from a Newbie

Hi There ... well I am a Newbie to this site but have been using Macs in all shapes and sizes fr a number of years .. but i digress...

I am a University Lecturer based in Portugal and we run a 7 Mac Mini edit suite
The specs are as follows:
4 Mac Mini 1.83Ghz Intel 2Duo 1GB RAM 667MHz DDR2 running 10.5.8
2 Mac Mini 2 Ghz Intel 2 Duo 2GB RAM 1067Mhz DDR3 running 10.5.8
1 Mac Mini 2.53Ghz Intel 2 Duo 4Gb 1067 Mhz DDR3 running 10.6.8

Ok as you can see 1 of them (the newest) is running Snow Leopard .. now I have some problems with the others , especially response times when running software such as Final Cut Express.
Would it make a huge difference if I were to upgrade all to Snow Leopard or even Lion ?
Or is it more a RAM issue ?
Is Snow Leopard still available ?
Is there any good software out there to improve reaction speed ?
I know that Mac Keeper is to be avoided ... yes have read the posts .. but how about Stellar Speed Up ?? Anyone used it any comments ?
We use Sophos Anti Virus .. anyone had any bad experiences with it ?
Is Lion all its cracked up to be ?

Thanks

Mac;D

RAM is the main issue, both the older models need at least 4 GIG to run programs like FCP well

Apple Mac mini Specs (All Mac mini Technical Specs) @ EveryMac.com

What's the free hard disk space like on those, a nearly full hard disk is going to effect performance.

You can buy Snow Leopard from Ebay, but all those machines can run Mountain Lion (with at least 2 GIG RAM), Mountain Lion which is inexpensive. Just make sure non of your vital applications are not older, pre 2006 PowerPC programs, they will no longer work in Lion or Mountain Lion

To upgrade all three, you have to doawnload it on the newer Snow Leopard one and create a bootable drive to install the others

But upgrade the RAM first, leave the OS upgrade for later

As louishen stated, adding RAM will be the biggest help. I may be wrong, but your Sophos Anitvirus probably eats up a lot of your RAM resources. Are you required by the University IT dept. to run AV?

I don't know about other schools but I know the college I am enrolled in requires all students to have AV software (even on Mac). I chose Sophos AV and so far have not found it to degrade performance much. My Mac is only a tad slower than it was when I first got it 6 weeks ago. Macbook Pro 13" 2.9ghz, 8gb RAM and 256gb SSD. It's not much of a resource hog at least in my experience. I don't know how it would affect a system with limited ram or slower storage such as a standard HDD though.

SophosUIServer is only taking up just over 11 MB of ram according to the Activity Monitor.

From what I understand, most schools require AV software for students and faculty.

Thanks for the replies ... the RAM is something i was thinking .. especially the older Mini´s .. about the new Mountain Lion .. is it as good as Snow Leopard ? I have heard conflicting reviews .. with some reinstalling Snow Leopard after installing Lion/Mountain Lion.
We chose Sophos beacuse I had seen a forum , not sure now which , that recommended it .. after steering away from Mac Keeper .. about the IT dept .. yeah they pretty much told me that it would be wise to arrange a AV program as the students use pens on both the main pc´s and the macs in our dept , which are always catching trojans and spyware etc. i turned on the Mac Mini the other day to find straight from bootup that it opened Safari and was on the Mac Keeper page downloading the latest version ...
needless to say i went straight to the downloads folder and deleted it ..
about the other program i mentioned Stellar Speed up ... anyone heard of it/used it ? worth the money ?

Mountain Lion = WAY BETTER than Snow Leopard.

Five Great Features of Apple's OS X 10.8 Mountain Lion - Forbes

Stellar speed up = scamware. Like MacKeeper.