Best upgrades for 2 machines? Video card or Memory

[Oisean]

Machine 1

Motherboard Asus M3A78-EM

AMD CPU (not sure which type but it's a Black series)

4 Gig Ram DDR2 800

Video card Sapphire Radeon HD6670 1GB DDR3

Windows 7 64 bit

Machine 2

Mother board Asus P7H55-M_PRO

Intel I3 3.4 GHZ CPU

4 Gig of DDR3 1600 

Sapphire or other Radeon HD 5779 1 GB DDR 5

 

The hope is to upgrade the memory or video cards on these machines to reduce the client side lag that is happening.  The first machine can ONLY take Radeon cards and maxes out at 8gb of DDR2 so not sure which would be better to upgrade on it.

 

The 2nd machine I was originally thinking upgrading the RAM as on the first but got to thinking maybe a decent Nvidia GPU would be better suited?  Thoughts on this would be appreciated.

[AiNt Ansar]

The Asus M3A78-EM supports PCI Express 2.0 x 16 graphics so supports Nvidia PCI Express 2.0 cards just fine. However, because that mainboard is at least 6 years old, the power supply unit will be old too. it's likely that your PSU will not provide sufficient power for recent mid to high range GTX cards. So when deciding on a graphics solution for either of your PC's.. remember to check that the PSU is up to the job.

[Oisean]

The M3 PSU does support 8 pin power for a GPU however the issue is I've seen a lot of information out there that the M3 only supports Radeon due to the integrated Video onboard.  Yes I know how to disable it but am curious fi that would work or not?

 

So looking like Video cards are the best option then?

 

[VRprofessor]

I am geeky enough that I start with 8GB RAM, although I am uncertain if it actually helps with running SL.  Can't possibly hurt and with the holidays here I have seen some decent sale prices on RAM online.

Graphics is the biggest bottleneck for SL and most of the time a graphics card is the way to go.  Like the previous poster I'm going to recommend checking the power supply.  Not only do you need connectors, you need enough power.  The low end GPU cards that will upgrade your computer need a minimum 350w - 400w power supply--and based only on comparision charts it looks like that will give you a modest improvement. 

If you get a more capable GPU it is going to want a bigger power supply--most recommendations I see are 500w or larger.  While power supplies aren't exactly cheap, online vendors put them on sale regularly so they won't break you.