The virtue of using VMs to aid laptop performance ....

Traditionally I have used VMs to emulate a server environment(like W2K3) or test some other OS like Linux. However is there value in optimising performance on a laptop by keeping database performance in its seperate VM core as opposed to the web server as opposed to the development environment, or is it still quicker to run all environments natively, using intel's turbo boost as well?

Thanks,

Sam

P.s of course VMs are great for backing up specific environs as well.

 

Because of the overhead (CPU, RAM, IOPS) associated with running VMs in a hypervisor that is not running on bare-metal, you would not gain anything performance wise by running a portion of your services in a VM.

 

OK, so it is better to run the dev environment, web server and database all on the native machine and OS. However can one take advantage by running components within their own core ie dev in core, web server in core 2, sql server in core3. Not sure how one would do this and whether it is worthwhile as opposed to running the whole lot ontop a punchy dual or quad core cpu.

Thanks,

Sam

 

@Indrek, Thanks for the comment.

I fully understand your dev use of VMs to keep it neat and tidy since my current laptop runs all the components natively ie IIS, SQL Server 2005. Thus if I am starting it up it takes a while since all these services need activating. Since one activates VS manually I could see an advantage in putting Using IIS and SQL out of a VM say running W2K3 which the live server runs. This way the heavy duty IIS and SQL stuff only runs when needed One can always use the local dev web server natively as and when required.

I take your point about the component core stuff. No need to worry, let the OS do its job !!

Final question about this is whether, in your opinion, there is really a need to use a quad core rather than a dual core ie i5 560M forgetting the RAM limitation of 8GB of the dual cores.

Cheers.

 

Thanks for this. Very useful. Out of interest which VM are you using?

Virtual PC, VirtualBox??? Other???

Interesting comment about Quad Core. Sometimes it is tempting to chase the biggest spec without realising that actually the i5s aren't that bad. Infact the i5 560M is the same as the i7 920M on turbo mode ie app not optimised for use all cores. It makes you think as the i7 960 is lot more expensive. However if you are doing 3D rendering then the quad i7 960 would be the ticket I guess. One unfortunate aspect to the dual cores is the lack of the 4 memory slots, just 2 which removes flexibility on RAM unless one intends to remortgage the house for 8GB sticks !!!

Cheers,

 

As developer myself I agree with all that's been said. It really depends on your requirements. If you spend much of your time as I do designing architecture for specific platforms then the consolidation aspect of VM's is hugely useful. I often have multiple software architectures implemented for specific platforms all running at the same time.

Any of the mobile core i5/i7's are easily up to the job. I've recently purchased an 8440p running with an i7 620. I've also got a high spec Precision m6500 as a development workstation, 16 gig RAM and a 920XM quad. Although I can have more VM's running at once on the Dell there's no noticeable performance difference with the VM's running on the 8440p. Both are such high-spec notebooks they run VM environments that feel as if you're working on a bare metal machine.

Personally from my experience of enterprise virtualisation it's RAM and disk throughput that count. You'd get a really decent VM host with an i5, plenty of RAM and an SSD.

As for the virtual solution I use VMWare workstation for my development environments and 2008 R2 Hyper-V for server based prototypes. Not a big fan of Virtual PC, single virtual CPU only and a rather screwed up implementation of virtualisation. Virtual PC is free and does have better legacy support though. You takes your choices....

 

Folks,

This is really useful. It is great to hear about people's different use and views of VM and I agree with them. Thanks.

I am now not rushing to get a quad CPU as the price difference is too high. The only question I have is whether 8GB will be enough since this is all I can get on the dual mobo and I think it will be. The point about using SSD tech is a good one and money spent on this rather than quad core might be money better spent. As I mentioned on another post I have found the retail price difference tween dual mobo and quad mobo models to be about £1K and more if I was to get a "HP Renew" model. I do have a MicroATX dev box which can take up to 16GB with a Q6600 Quad CPU. Also the 8740w has an eSATA port so one can run VMs off this seperate SATA channel and drive which I guess would speed things up. It just comes down the one's real RAM requirements.

Thanks again,

Sam

 

oh sam i was going to say.

you can also get ExpressCard SSD drives now too.

I forgot to say - i run my VM's via the SSD in my ExpressCard Socket.

its a verbatim 64GB one, runs at 144MB/sec Read - 44MB/sec Write

I dunno what they cost in the UK, i bought mine out here for ~£85

but it eases the pressure on my more expensive 240GB OCZ SSD using windows Server 2003, which DOESN'T support TRIM.

Just to bear it in mind - it's a cheap upgrade for a slot that i used to keep a spare tenner in for when i was working down the pub lol.

 

Ever since we last chatted, have been spotting "Ferret" beer at parties and drinking !!! Very nice !!!.

Good idea about using the ExpressCard Socket. Did not think of this.

Cheers,

Sam

 

Hi All,

Dual core i5s have 2 physical cores and 4 hyperthreads which is a simulation of H/W cores. How do VMs exploit these hyperthreads? Ie can they work out as effective as having 4 physical cores for VM use?

Cheers,

Sam

 

Short answer? No, it won't be as effective as having 4 physical cores, and this is the case for any use.

For a longer answer, you can go through my explanation in this thread. Essentially, hyper-threading lets you simultaneously schedule 2 threads on the same core, but they'll end up sharing the core. We have no numbers for exactly how much of a bonus hyperthreading adds (I think a long time ago we had a discussion on the dual-core/quad-core with benchmarks, and the benchmarks seemed to show that the bonus was around 10%), but note that this bonus is compared to a processor without hyper-threading.

Now, if your VMs aren't heavy on CPU usage, you may not notice the difference, but I'm not familiar enough with VMs to know how much load they place on CPUs.

 

Thanks for this, as I suspected. Hyper threads apart, it is amazing how competent the i5 dual cores are since most used software does not make use of quad core. Probably in my case the only only one would be VMs and that is if I am running more than one. Usually I just start one up to serve as a server or as a special client install rather than have multiples representing web server, db etc etc....

Sam