T520 2720QM battery life and graphics question

[bwalex]

Hi,

I've been a long time Thinkpad user and am thinking of buying a new one now. I am considering the T520 with a dual core and a quad core. I do have some questions regarding the quad-core:

1) Can I simply disable the discrete graphics on the quad core? I absoutely don't need anything but the integrated graphics.

2) How is battery life of the T520 with the 2720QM processor in comparison to the 2620M ?

Thanks,

Alex

[lead_org Microsoft MVP Contributor]

Before you purchase a laptop can you tell us a little bit of what you want to use it for?

you can get the T520 with only integrated GPU, also the price of a T520 with quad core CPU sometimes can cost as much as the entry level W520 with the same CPU.

[bwalex]

I know what I want, that is not the question. I know I can get the T520 with only integrated graphics, but then I can't get a quad core. All quad core T520 come with discrete graphics. I don't want a W520, I want a T520. I simply don't need even better discrete graphics, which is the main difference....

I only want to know whether I can disable the discrete graphics on the quad core T520 in the BIOS or not, and how the battery life changes with a 2720QM with respect to the 2620M on an average workload (document editing, web browsing, etc; in other words Average Joe's work).

Kind Regards,
Alex

[benc]

I'm expecting delivery of a T520 quad core this week. I'm hoping you can disable the discrete graphics in the BIOS as I have no need for it, and would much rather have better battery life. I'll let you know how I get on.

[ColonelONeill]

W520's get higher resale value in the future though. If you ever run into a case where whatever you're planning to do on a quad-core CPU becomes CUDA-friendly, then that card would help massively.

The quads have 10W higher TDP, but in basic usage, I think it doesn't matter.
http://blogs.technet.com/b/keithcombs/archive/2011/03/28/lenovo-thinkpad-w520-mini-review.aspx
This review here suggests 6-7 hours of battery life on the quad, but he has Optimus enabled. That said, under ideal conditions, Optimus shouldn't enable itself on basic productivity workloads.

[Q-Ball]

Having a quad-core processor doesn't take a huge chunk out of your battery life.

From what I can understand from early reviews it's as good as an Arrandale (i7-620M) dual-core T510, which has an NVS 3100M GPU: about as good as Sandy Bridge integrated graphics.

You should be getting the maximum possible battery life with that usage scenario since the laptop's CPU will be close to idle.


Remember that if you want Optimus to kick out and just use the integrated graphics you need to go to Windows 7 Basic.

But you do know that the W520 is the same thing as the T520 just with a different motherboard, processor, and graphics card, right?

They could have just gone with the model number T520p, actually. It's all the same chassis.


But why are you buying a T520 with a quad-core processor if you are only doing basic tasks?
You could save yourself quite a bit of cash and just go with the i5-2520M.
If you wanted an upgrade to that you could go buy an SSD, but to be honest you don't need quad-core processing power if you're using it just to browse the web.
Besides- the quad-cores already have great battery life and the dual-cores should, in theory, extend this even further.

[bwalex]

I am aware thaet the t520 is just the same as the w520 with, most notably, a different graphics card.

The workload I mentioned is far from my average workload, it is just what I think most people will know about. I normally run one or two VMs and spend quite some time compiling things, doing engineering calculations with Matlab, synthesizing FPGA designs, etc. That being said, I have until recently done that on a old c2d t7200 and it wasn't too bad, so I could live with a dual core if that means a much extended battery life.

As you can see from the workload above, I do need computational power but definitely not the discrete graphics, not even CUDA is of iterest to me. The decision is essentially whether the trade-off between CPU multiprocessor performance and battery life is worth it.

[ColonelONeill]

I thought MATLAB could do CUDA now?

In some locales, a similarly specced W520 (with the better GPU) is only a hundred dollars more expensive than the T520 counterpart. More of a just in case and/or resale value consideration.

[bwalex]

Thanks, but even if I was to consider the W520, the question whether to go for a dual core or quad core remains In any case, better GPU or resale value aren't important to me; not sure about Matlab using CUDA nowadays or not, I don't use any too recent version.

Thanks,

Alex

[bwalex]

---

benc wrote:

I'm expecting delivery of a T520 quad core this week. I'm hoping you can disable the discrete graphics in the BIOS as I have no need for it, and would much rather have better battery life. I'll let you know how I get on.

---

Thanks, I'm looking forward to hearing how it works out for you!

Cheers,

Alex