What CPU is best for Virtualisation?

[OurPuma]

Hi all. I'm after a PC to run around 8 VMs at one time (max) - but normally only around 3 or 4 would be running. The PC will have at least 16GB DDR3 RAM. I used to have some kind of AMD 6 core CPU around 6 months ago for a year until I had to give that loan PC back. It is to run my MS server 2012 host with Hyper-V running all VMs to begin with. The AMD chip was good but I noticed slow down when running more than 4 VMs. Does anyone else have a similar setup? I have priced items on ebuyer and Intel Core i7's 3770K is coming in at £250 - but the AMD 8 core 8150 is only around £140. The Intel i5-top of the range was £170. Which to go for?

[tom999]

What are the VM's doing? I run a lot of vms. Thet are always ram bound before the CPU is an issue. A decent i5 will prob be fine. SSD makes a huge difference.

[OurPuma]

Thanks Tom. I hadn't even contemplated an SSD purely through cost. But.....they have come down in price recently...I will take a look, they aren't something I've had much experience with yet but they can't be that hard! It will mostly be Microsoft VMs perhaps with Ubuntu too just to sit some MS exams, so like domain controllers, exchange server, terminal servers, client pc's. So it might be better to get a cheaper i5 ivy bridge processor with more RAM and an SSD....

[Over Carl]

I've got a box at home with 2 x xeon e5310's - should be 2 x 1.6 quads but overclocked to 2 x 2.0, 24Gb of RAM, 9 x 146Gb 15K SAS drives for the vm's, 1 x 73Gb 15K SAS for the swap files and I'm booting ESXi of a flash drive.

It's currently running 16vm's happily, ESXi allows memory overallocation and I have about 48Gb granted to my vm's even though I only have half that in actual RAM.My VM's are pretty much like yours listed, also running a router and VOIP server.

If at home where expensive licensing isn't an issue I would definitely recommend ESXi over Hyper-V. However if licensing is an issue, they have really messed with the pricing on ESXi 5 so in some cases there isn't actually any point in virtualising with regards to purchase costs.

The only real issue I'm facing is that ESXi creates a swap file as large as all the memory granted to each VM as soon as it boots - i.e. if you have 10 VM's each with 4Gb RAM and a 32 Gb swap drive, you can only boot 8 VM's. I wanna max the box out with 10 x 300Gb 15k SAS, 256Gb SSD, 64Gb RAM and 2 x 3.0 quads but this takes a lot of money I haven't got. My temporary sticking plaster fix I intend to do soon to give me a little more to play with is to change the drives to 10 x 146Gb + 120Gb SSD for swap.

Obviously the newer the cpu and the higher the clock speed the better, as well as more cores coming in very useful. However I believe apart from performance the only relevant developments with regards to cpu's and virtualisation are VT-x (Intel) or AMD-V (AMD) and VT-d (Intel) or IOMMU (AMD).

Anything at all recent will have VT-x/AMD-V so it's not worth bothering about them unless you are looking at ancient kit (before around core 2 duos) in which case it's worth checking.

VT-d/IOMMU is interesting - came in around about when the Nehalem architecture came in (i.e. the i3/i5/i7). With this for example you can have a copy of ESXi running as a VM on another copy of ESXi, and the ESXi VM is perfectly capable of running it's own VM's. Also allows passthrough of certain stuff so for example you could add a dedicated NIC for a VM, then using passthrough not only would the NIC be totally isolated and dedicated to that one VM, the VM can use the proper drivers for the actual device rather than using the simulated Intel E1000's which do work but aren't the fastest things in the world, or the vmxnet drivers which don't work with everything.

You don't need to purchase a real server to do this but I would advise it - if you don't care at all about loosing all your VM's then it's not important but it's not fun putting hundreds of hours into testing configs then losing the lot once you're pretty much done (happened to me once). Reasons I would recommend a real server - get one with a battery backed RAID controller. Onboard RAID is cack at RAID 5 writes and proper RAID controllers have less problems than onboard/fakeraid solutions. I would want these in a server with hotswap drive bays so you can change a failed drive without powering down and you even get a little blinking warning light if a drive fails (I really need to implement a monitoring solution to email me when this happens but haven't got round to it). Also unless it's just a handful of very lightly loaded VM's, I would definitely want either SSD's or 15k SAS drives for the VM's. Desktop SATA drives may claim to be high performance but when they are getting caned they just don't compare. Other bit of a real server I value for this kinda stuff is ECC RAM. Believe it or not, cosmic rays can mess with your RAM, ECC makes it very unlikely that this will cause any data corruption or crashes. In fact I don't think I will ever purchase even another desktop for myself without ECC. Final bit is that real servers normally come with remote access cards or IMPI so you can remotely power cycle the system and other stuff.

[OurPuma]

That sounds like an ace setup Over Carl. Can I ask what box you are running that on? Is it an old generation Dell or HP? I had been looking on Ebay at older HP ProLiant DL320s, DL380s, ML350s, and Dell PowerEdge 1850s,2850s but with regards to actual usage and setup costs i'd still be better off buying something......that wouldn't chew through the power and possibly break out of warranty within months of usage (and take up loads of space + rack+ cabling - which I don't currently have) .I have MS TechNet Pro subs so MS licensing isn't a problem. I don't have any VMware experience - well not since 2007! And the Vt-d sounds perfect. I can sense my cost comparison excel spreadsheet might be getting updated with some new hardware!

[Ashley]

Off topic slightly but what do you use all these vm for? I always read and wonder why you'd need them.

[OurPuma]

In my case it is to create my own domain and to replicate a typical SMB business IT infrastructure. And to play with different OS's....

[reverend]

You can pick up cheap Dell CS-23's from eBay which are nice bits of kit too with the Intel L5410s - they support everything except SLAT so you wouldn't be able to do RemoteFX but other than that they are cheap and do the job nicely. Just mind they're not quiet!

Otherwise what about picking up a couple of cheap Microservers and running the load across both? They aren't the quickest CPU but handle more than you would expect for the price (roughly £120 after cashback) and they're as quiet as you'll get!

[Over Carl]

In my case it is to create my own domain and to replicate a typical SMB business IT infrastructure. And to play with different OS's....

Ditto.

You can pick up cheap Dell CS-23's from eBay which are nice bits of kit too with the Intel L5410s!

I wasn't familiar with these models - are they older versions of what Dell now call their C Series servers? Do they also not let you run OMSA and have no BMC/IPMI? Damn cheap for what they are on ebay however.

I tried out a few servers at home before (varying from 1u and 2u units all the way up to a poweredge 1855 blade enclosure) - I found they were all way too noisy cos of the small fans (except the 1855 that just way ott). That's one of the reasons I've settled on poweredge 2900 for myself - the big fans don't make a silly racket. Watch out if you are looking at these though, 1st revision only take dual core cpu's, 2nd take xeon 5300 series and the 3rd take xeon 5400 series.

Also if anyone's interested, I know how to modify xeon 5300's with a 1066 fsb to 1333 or 5400's with a 1333fsb to 1600.

I've also modded my pe2900's bios so it won't flash errors if I put slower fans in, but apparently this doesn't agree with 15k sas drives so I never purchased/fitted slower fans.

I've had some poweredge 8 gen models (x8xx models) and they are a little too old for any real fun with virtualisation. Virtually all are single core but some were specified with dual core cpu's.

The warranty on my box expired a week after I got it, it's been running for nearly a year with just one drive failure (quite likely because it was in an unventilated room and the vents were all blocked during the hottest week of the year). Tbh except for drive failures (or less likely, psu), they tend to carry on doing their thing.

I hadn't even seen ESXi before last year, didn't take me long to figure out what I needed, since then I've even got a couple of ESXi boxes in production at mate's offices happily doing their thing.

[tom999]

Be wary of the noise and power draw of old servers. I used to run 2x dell poweredge at home. Check power draw with a kilowatt plug.

If it was me I'd build a 32gb whitebox. 1tb hdd, and as much SSD as you can afford. Agree raid is nice if you can afford it.

Esxi is great, and all serious enterprise use it, but if you're doing msft exams stick with hyper v IMHO.

[OurPuma]

the older servers would be great....if I could have them somewhere else to play with like at work .... but I work from home and the extra noise and space would be OTT. Though it would be awesome! The micro servers are a little more limiting but again a good option. Much to ponder! Over Carl - have you tried GFI Max - I used it in my previous job and it would highlight failed disks on our proliant servers within 30 mins via an alerts dashboard that we could login via a web interface.

[Over Carl]

I worked at a place where we had some gfi stuff that I wasn't too keen on. I've set myself up an ubuntu box with nagios and mrtg but I need to apply a patch to query my ESXi box via SNMP that I haven't got round to.

[OurPuma]

I've taken the plunge with the HP Turion Microserver from Ebuyer with the £100 cashback and extra RAM. Decided noise & size was the main factor in choosing this. I can always get a higher-specced PC later.

[Ashley]

I've taken the plunge with the HP Turion Microserver from Ebuyer with the £100 cashback and extra RAM. Decided noise & size was the main factor in choosing this. I can always get a higher-specced PC later.

I use mine as a media server and its silent and in the year I've had it hasn't gone wrong once.