Hardware for running lots of VMs (up to 200)

[tosstoss]

 

I already got a server I built at home with xeon e3-1246 CPU, 32 GB of ram which can run up to approx 40 vmware virtual machines at the same time. The RAM is the bottleneck there (the cpu runs at 40%-60% load all the time according to task manager, is it an accurate representation of how much "room for work" the CPU has or are there better ways)? The VMs I run use the most low spec windows xp config thats possible - 512 MB or 1 GB ram and 1 virtual CPU. A few browser windows (firefox chrome) are opened on every VM and new pages are loaded on them a few times per hour - everything very low on CPU usage as you can see.

 

Now my question is - I want to build a second, more powerful server from scratch - what would be the best CPU that suffices for 128 GB of RAM and running up to 150-200 of such VMs?

 

I created this config:

 

mobo: msi X99A raider

CPU: 4 core xeon e5-1620V3 or 6 core Xeon E5-2620V3 (initially I thought about i7-5820K, unfortunately I found out it supports only 64 GB RAM so I am thinking now about the e5 supporting 728 GB)

RAM: up to 128 GB ram consisting of sticks: crucial 16 GB DDR4 2133 mhz reg ECC

graphic card: gigabyte GT 730 ultra durable 2 silent

storage: samsung 850 evo ssd

 

Do you think that the e5-1620V3 will suffice for running up to so many VMs (although they are very low on CPU usage)? The next better e5 is the 6 core xeon e5-1650, but it costs twice as much (300vs600e) so I would like to stay with the e5-1620V3 if possible. Also what about the reg ECC RAM, does it help when running a lot of VMs 24/7 (ocassional restarts few times a week are ok)? ECC ram support was the second reason apart from the big ram support that I am looking at xeon processors (the mobo supports ECC too). How is the e5-1620v3 compared to the e3-1246 CPU I have in my old server?

 

Looking forward to any help, comments and suggestions to my whole setup and questions, thanks!

[schoondoggy]

Here is some light reading on sizing:

https://blogs.vmware.com/tam/files/2015/01/VM-Right-Sizing-Best-Practice-Guide2.pdf

200 is a lot of VM's. Even if they are not doing much that is a healthy load.

If a a E3 with 32GB of memory will run 40 of these VM's, 5 times the memory (160GB) could be enough. 

E5-2670 are on eBay for around $105.