8-way single core vs 2-way QUAD-Core

[ctsadmin]

To help save money and get better use of our VMWare CPU licenses, I am thing about replacing our older HP DL 740 8-way single core Xeon 2.70 Ghz with a 2-way Quad core DL380 (3.00 Ghz) (8 cores total). This will free up 6 CPU licenses that I can use for further hardware purchases.

Should I expect the same type of CPU performance from the 2-way quad core that I have getting from my old 8-way box? I know there are memory issues to think of, but that is not my concern with this project.

The math tells me YES but common sense is telling me NO.

Any thoughts?

Thanks!

[mreferre]

You should expect higher performance. The internal core engine as well as the memory architectures has drastically evolved over the last 3+ years (i.e. compared to the single core engines).

I am not saying you should expect, on the new "dual-socket-4 cores" system, 2x the performance that you are getting out of the old "eight-socket-1core" system...... but.... it's certainly going to make it better.

Massimo.

[ctsadmin]

Really?

So in your opinion, if I owned 8 ESX CPU licenses that are currently bound to one 8-way server runnning 40 guests, I should be able to replace that server with a 2-socket Quad-core to run those same 40 guests and be able to purchase 3 more 2-socket Quad-core hosts and quadrulple my capacity without needing to buy another ESX license?

Sounds good to me!

I realize the architecture on the newer multi-core procs are more efficient, but I always thought 4 socket single cores>1 Quad-core.

Thanks for the reply.

[mreferre · Accepted solution]

Well, in theory not only that .... you would also be able to lower the CPU usage on the new 2-socket because of the greater efficiency of the new cores (and you could use these extra cycles to gain more flexibility in scheduling your 40 vm's or even put additional vm's onto it).

This obviously assumes that you can at least put as much memory on the 2-socket systems as you have in the 8-socket. This, along with # of PCI slots is what still set the high-end systems apart. The risk is that you have to buy very expensive and more dense memory for the 2-socket (due to limited # of slots) to match what you have in the 8-socket systems which have far more dimm slots.

Massimo.

[jamieorth]

Another consideration is having multiple hosts - are you saying you just have one? Then I would easily go the route of Dual Quad Core and possibly adding a second or third host. Do you have a SAN for centralized storage. If not look at LeftHand Networks - they can take your onboard storage and make it appear like a SAN to your ESX hosts.

If you want to stick with a big box, why not wait and get HP's DL785 coming out in may. An 8 way quad core - all wrapped in a 7U package....:p

[mreferre]

Well so let me use this space too for some AD.....

> If you want to stick with a big box, why not wait and get HP's DL785 coming out in may

.... or you can buy today a modular (4+4) IBM 3950M2 that you could deploy in an "8-socket" config or in a "4-socket x 2" config etc etc etc .....

Massimo.

[jamieorth]

Ok, I like that one also....I just mentioned the HP becuase that's what he had now. I am brand agnostic......Well, I take that back. I love whatever the boss lets me get....

[JDLangdon]

ctsadmin wrote

"So in your opinion, if I owned 8 ESX CPU licenses that are currently bound to one 8-way server runnning 40 guests, I should be able to replace that server with a 2-socket Quad-core"

How many cores do you have in your one 8-way server? The last time I looked VMware licensed Esx by the number of sockets, not cores. Unless you have one server with 8 CPU's you shouldn't need 8 Esx licenses for one server. Your new server with 2-socket Quad-core, is still only 2 sockets and therefore, requires 2 Esx licenses.

Jason

[williambishop]

I think he got it Jason, because he mentioned he could do the exchange and then buy 3 more of the hosts and use his current licenses.

[wilcox71]

I think the 3850 M2 can scale to a 16 way if I remember correctly.

[mreferre]

Right now (11 April) 2 chassis "only" would be supported.

Consider that 2 chassis already make 32 cores ... which is the limit of ESX today anyway...

Massimo.

[jamieorth]

So, 2 chassis for 32 cores = 8U of space. The DL785 is 32 core, 7U of space. What is the power consumption of 2 chassis along with the BTU output?

[mreferre]

The power consumption of the 2 chassis is 2 x the power consumption of a single chassis. You can build your own config with this tool here:

....and get precise numbers in terms of Watts / BTU's.

Massimo.