Best RAM for vSphere

[ilyaca]

Hello,

I've purchased an Intel S2600CP4 motherboard along with two new Sandy Bridge E5-2600 processors.

I was thinking about the best RAM for my system, I want to have 64 gb of ram. What's the best option? I've already purchased 32gb of 1600 mhz Corsair Dominator but now I understand that it's not a "server" RAM, more of a "gaming" ram. Is it a good ram? Will it affect the performance of my VMs running on vSphere? Should I get another 32 gb of Corsair Dominator? Or should I get 64gb of another brand which was designed for server use? How bad is it to mix RAM of different manufacturers on a single server?

What's the best ram you would recommend for such configuration?

Thanks!

[peetz · Accepted solution]

When choosing RAM for vSphere I would make three basic recommendations:

1. The more the better (but be aware that the free license can only use 32GB and will refuse to start if you have more than that)

2. The faster the better (I think 1600 MHz is good)

3. Should run absolutely stable in your system.

So, thoroughly test you RAM (with memtest or similar tools) for system stability.

For me it doesn't make sense to recommend a specific brand. Even with "server grade" RAM you can have a bad chip that leads to instability. So testing this is the most important thing.

- Andreas

[kjb007]

Server RAM is typicall error correcting, and registered, which is usually why it tends to be a higher cost.

That being said, server RAM is also not always the fastest RAM on the market taking.

Very rarely will you have RAM speed being a bottleneck.

If you're ok with the memory not having those advanced features, you should be fine with just about any brand.  Go with a known brand, so you know the chips will be good and you have someone with good customer service to talk to if you do have problems.

-KjB