Intel vs. AMD Architecture. Worth the switch?

[admin]

I understand the largest benefit of the AMD architecture is the larger addressable memory space with increased performance with higher memory configurations as well as the cpu compatbility between generations. I know vmotion compatibility in the past was always a concern for Intel consumers because of the difference in the cpu architecture amongst generations for compatibility reasons. I understand there is now the CPU masking feature part of virtual center and flex migration technology in xeon processors that negate this concern (I believe). So my question is, if we already have an investment in intel technology in our esx environment and will likely never run more then 64gb of memory per host, then is it worth the cost to try and migrate to AMD hardware? Are we going to see a noticeble performance difference for the cost we are going to encur in making such a transition? Imo it is much easier for us to add an additional intel host as necessary. Trying to bring in AMD we are required to either a) buy two hosts at the same time for vmotion compatability which is limited to the two of them or run one amd host without HA ability until we procure a second. our current environment is based on xeon e5420 (2.50ghz) cores.

I am interested in gathering the thoughts of others on this topic.

[Sappo-manno]

Hi Scott,

since you speak about e54xx I'm guessing you are using two sockets server. Did you consider servers based on the Intel Nehalem platform? The 55xx are nice quad core chips and the chipset supports up to 144GB of DDR3 @ 800 MHZ and up to 96GB @ 1066MHZ. You could still perform vmotion VM between 54xx and 55xx by using EVC. So I don't see a need to migrate to AMD if you are already on Intel. And did I mention that those Nehalem are quite fast?

Cristiano

[JohnADCO]

What do you expect it to gain you?

I mean, the average host with multiple VM's has so much going on, you really only talking small parts of the entire performance equation by switching CPU speed / platforms. In my opinion anyways.

[admin]

Its not really what I expect it to gain as much as the inquiry as to whether or not its worth it. Dell specifically has been really pushing the amd's on us for our virtual environment claiming their improved performance over intel in virtualization is signifcant enough to justify. To my knowledge this may be the case but not until you start hitting the super high specs. Like 128gb of memory multi socket cpu's (4+). The advantage I can see is the generation compatability but aside from that and perhaps improved performance for higher spec'd hosts with oodles of memory, its not really advantageous. And with the processor's we are already using now, I dont see this generation issue being, well...such an issue going forward.

Thats why I posted. In hopes of gaining some opinions from others that have decide either aye or nay to this.

[DSeaman]

I would look at the latest benchmarks. It seems the new Intel Nehalem processors blow away AMD. Personally I was going to buy AMD HP blades, but now I'm changing our order to all Intel Nehalem based blades (BL490c G6).

[zgilb]

You may want to consider whether PVI/VMI+64bit is a requirement for your setup or not. I just posed this question to this forum as the AMDs can do 64bit PVI guests, and the Intel 54xx cannot. No one seems to know about the 55xx in this respect.

[meistermn]

What about the esx scheduler?

Nehalem 2 socket ( 8 cores)

18 dimm slots with max 144 GB and 800 MHZ speed

7 cores and 1 for esx service console. 8 native threads and 8 hyperthreads (Hyperthreads can only get 30 % of the native threads !

Intel VT-d could be an advantage . But till now no performance values available.

AMD 4 socket server (16 cores) .

15 cores and 1 core for the service console. 16 native threads. Advantage better parallel queing and/or better garantied MHZ.

32 dimm slots with 128 (256) and 667 MMZ speed.

Both are plattforms near equal priced when both use same ram capacity.

[MikaA]

Disclaimer: we are currently AMD users.

Personally I don't see much point in flipping between architectures. Ẃe've been happy AMD users for some time and even though our environment isn't large, we have no intention on switching to this newest-and-greatest-architecture-released-yesterday, whichever it was this time. There has been and always will be new and great platforms and architectures that are better and faster than those invented last year.

I believe you should plan your environment, how many hosts you will need within the foreseeable future and in what timeframe will you be buying them. Then you make a decision for platform, be it Intel or AMD, and then you stick with that. You may not always have the latest and greatest CPUs but you will have minimized your migration and compatibility problems.

Yes, Nehalem is great and it's better than current Opterons. Well, no shit? Those Opterons are basically a six years old design. But, istanbul is here in a couple of months and that's "good enough" in regard to Nehalem. A year from now and we should have Magny-Cours. Meaning, AMD may be a small step ahead or behind of Intel next year at this time. In any case, if you always "doubt" your platform decision you will always be asking yourself (or this forum) whether you should switch or not. And that's a waste of time.

We've been happy with AMDs let's-not-change-everything-every-two-years strategy and plan on staying on "this side" going forward. So all in all, I would say you do your math (there won't be huge differences in CPU performance in the long run either way, take a look at roadmaps (AMD just updated theirs), think about the potential benefits (you won't get any "oh my god I can't believe how much faster this is!" gains) performance/money/upgradeability/longevity/whatever-wise and switch if you feel that's the best choice. And try to look at least 1-2 years ahead, otherwise you'll be doing that again quite soon.

With all the hardware virtualization stuff being added by both I'm guessing it won't take that long when you don't necessarily have to worry about these things and you can mix and match architectures more freely, which should make life easier in the future..

.Mika

[meistermn]

I think in a different way.

Lets say you have a small enviroment with 25 x 4 socket esx hosts with dual cores and Quad Core only Barcelona. On this enviroment are 300 VM'S running.

This means 50 x 2 ESX Licences were bought . For Enterprise this means 50 x 5000 = 250.000 Dollar.

If I now have to go from 300 to 3000 VM's, than a plattform change does not matter. It is only a power off and two reboot for the VM. So if at that time AMD or Intel is faster or new virtualization features than you can choice at time the faster cpu vendor.

If you only want to go from 300 to 600 VM then you have two options.

1.) Buy new servers and new vmware licences .

2.) Or replace all servers , maybe only cpu (AMD Istanbul) and pay not for new licences and get double of the vm's.

So it comes all down to at which time to replace new server or even buy server. And when the vmware enviroment is big, then a relacement of the existing server is the bestinvestment.

Let's they 200 x 2 ESX Licences . This menas costs of 200 x5000 = 1.000.000 dollar for vmware licences. If this farm runs today on AMD Barcelona, and Intel Nehalem is double fast, and the servers have to be replaced now in may than I would do it. If have the chance to wait till aug. for Istanbul

and if Istanbul is as fast as Nehalem EP then I would choose AMD. If you are now an intel shop than it is clear to go with nehalem.

[mreferre]

Lets say you have a small enviroment with 25 x 4 socket esx hosts

?!?!?!

Small? You should meet with one large SMB shop in my GEO one of these days. The large might have 20-30 Windows servers... the small might have 7-8.

In a scenario like this I am with Mika.... adding 1 or 2 hosts with 2-sockets to an existing cluster (of 2 or 3 hosts) is a nightmare if you start a flip-flop between cpu vendors. On the other hand if your project scope is SO big and SO dynamic than it might make sense to spend time looking at the best technology at a given point in time.

Massimo.