Dual or Triple channel configuration for gaming?

Apr 20, 2017
Hey guys,

one of my friends needs an upgrade of his rig, because it's quite old and he's starting to experience lag in games and even during everyday tasks.

I found a great mobo bundle, which I think will do a great job: supermicro server motherboard, Xeon L5640 (6c/12t) and 20 GB (5 sticks X 4GB) of DDR3 RAM (costed me 105 £ delivered)

I think the original owner used to run 6 sticks, which is the maximum (24GBs) in triple channel, because the motherboard does support that. However for some reason he took out one of the sticks and the bundle only came with 5 of them, which leaves me with in an odd position.

My friend would probably be doing light gaming (LoL) and potentially streaming, with a browser with a few tabs open during that. I know it's usually productivity tasks like video rendering that benefit from a lot RAM on multiple channels, so that being said, how should I configure the ram?

I don't think I can really justify buying another 4GB stick of ram just to run 24GB in triple channel, because I don't think he will ever be using that much. However I don't think running RAM on 5 slots (as it is at the moment) will be a good idea as it will neither make full use of the two channels that are fully occupied (from what I understand 4GB will be used in triple channel from each channel and the other extra 2 X 4GB won't be triple channel?) - am I wrong on this?

What I am gravitating more towards is leaving the 3rd channel's slots empty and only filling the other ones, which would provide 4 X 4GB = 16GB in dual channel, which would be sufficient for his use and sell off the 5th one, since ram prices are high at the moment - this will make this build even cheaper.

The other option I see is to leave 3 sticks x 4GB = 12GB in triple channel and sell off the extra two, but I don't think triple channel will make much of a difference for his tasks in such a degree, that I'd rather him have 12GB triple channel than 16GB in dual...

I know there's a lot of resources online, but this seems to be a more unique problem than what most posts cover and also there's the problem that the RAM sticks are an odd number (5) and I either have to sell one or buy an extra one.
What would your suggestions be?