What is Intel vt-d and how will it benefit me

Ok i am currently debating whether to get a 2720qm and 2630qm, I would get 2630qm but i will be running VMWare and was told i should get 2720qm for vt-d. But i don't know what benefits i will get, if it was a cheap upgrade i would not give it so much thought but it will cost me a lot. I am considering the HP Elitebook 8560w after a failed Alienware. There is a preconfig model for the HP for 2100$ which is perfect for me, but it comes with a 2630qm, and to get the 2720qm i will have to get a customized model which will cost 3400$(but i will probably get a M4600 if i need a 2720qm, that will cost me 2300$). So how will i benefit from vt-d , i mean what exactly will it do.

 

This stuff should help.

IOMMU - Wikipedia, the free encyclopedia

To VT-d or Not to VT-d? A guide on whether to Utilize Direct Device Attach in your Virtualized System? – Intel Software Network Blogs - Intel® Software Network

Understanding VT-d: Intel Virtualization Technology for Directed I/O – Intel Software Network Blogs - Intel® Software Network

 

The links are one thing to read but if you don't know what VT-d is then likely you will not ever need it.

 

That may be true.

However it does have a good amount of benefits if you are doing heavy work with VMs. It also allows you to use external resources via PCI passthrough.

Whether it is worth it or not is hard to say without knowing your requirements. The intel CPUs without the VT-d and AES features are much cheaper.

 

indeed they are the OEM types, I do rarely use vt-d, and I work making programs for linux, and windows all day

 

I can see vt-d useful if you have some custom PCI cards that you want to make exclusive access-wise to a VM (ie: through Xen). But on a laptop, its pretty hard to fathom any reason to have vt-d.

 

I worked for 25+ years as a Systems Programmer with the IBM VM(Virtual Machine) operating system. So, I know more than a little about virtualization type stuff. VMWare and the other virtualization OpSys basically ripped off the guts of IBM VM, as it has 40+ yrs development built in.

Direct attachment of devices to a specific Virtual Machine saves mips big time, so -IF- you have a situation where you can use it, you should definitely consider it. Big time I/O by a VM to a non-shared device would be a likely candidate.

As mentioned in some of the above links, what you mostly give up is flexibility, in that no other VMs will be able to access that device while it's dedicated to a specific VM.

As usual in these cases, run some tests and let the numbers dictate what changes you make.

 

How did they do that? Didn't IBM take legal action or something?