Thinkpad T420 Owner's Thread

I decided to follow "Shleepy" and installed a Core i7-2720QM Quad Core inside my T420. Apart from the tricky bezel everything else was a straightforward swap, no special modifications were necessary as everything boots up from the go. I didn't buy the processor from Lenovo, they wanted at least £1200 for it which is ridiculous! I bought it from HP who wanted 6x less than what Lenovo wanted, plus there's the bonus of it being genuine compared to the ES/QS test samples from eBay.

Needless to say the Quad Core is power hungry, I would advise people to have at least a 90w power brick to run this thing. During a stress test the system was drawing almost 63 watts so I can imagine throttling issues for those using the standard 65w power brick with this combination.

I'm going to do checks over time to see how it performs in the long term, so far it tends to be around mid 40's in idle which is pretty decent considering the chassis wasn't originally designed to take this sort of processor in the first place. During stress however it gets rather toasty being around 85c-90c which is borderline considering the TJunction of the processor is 100c.

It's an interesting experiment having a Quad Core 14" Notebook, certainly helps with my VMWare but for those who value battery life and quietness I would advise them to avoid this sort of thing to their T420!

 

can you please report how much increase in fan activity (is it on a lot more frequently? speed much higher? does it stay on for a lot longer?) are you getting with QUAD CPU, and what kind of usage are you talking about (word processing, browsing ... or more heavy like photo editing, OCR, VMWare, etc)

 

Hooray! I'm glad you decided to give this a shot as I am eager to learn about this mod. It is also nice to know you were able to do this on a T420i, which is the model I was interested in getting (I didn't want to drop ~$700 to find out it would only work on the T420 with discrete graphics only). Looking forward to your test results! Also, which power supply does the T420 ship with standard?

 

From what I observed so far fan activity is quite constant in order to maintain the mid 40 temps during idle, HWInfo32 reports fan activity of around 3200RPM but I found this around the same level (noise wise) to my T61 on idle.

Though if you're using TPFancontrol then i'm pretty sure you can override this but given you have a Quad Core in a small chassis I didn't really feel comfortable leaving the fans in passive mode. On normal usage which for me is internet browsing, Photoshop and firing up the VMWare, during load it can vary between 55-60c but then after it settles back down around the high 40s which is reasonable.

As standard you should get the 65w power brick, but if you're planning to put a Quad Core in then its inadequate as the CPU will consume a lot of power leaving little overhead. You need to bump up to at least 90w to be on the safe side.

At the moment its still too early to say whether it is a good idea putting a Quad Core inside a T420, doing stress tests really pushes the cooling system to the limit. I managed to get one core around 96c which is not far off from shut down (or boiling point for that matter). As I only recently just applied AS5 you could argue it hasn't broken in yet to achieve optimal results, but we see over time. Given I was using the Integrated Graphics model, i'm questioning whether it is feasible combining Quad Core + Discrete Graphics on the same cooling system.

 

^ Do you think Lenovo doesn't spec this as an option yet because it's too hard to keep cool? I'm sure their R&D has a bunch of machines running quad cores as we speak...

 

Hearst, where did you purchase Quad Core chip anyways for future references?

 

Possibly that, as well as power consumption, and the ability to separate your W-line from the more portable models. I also think that Lenovo's core market (businesses, not enthusiasts) wouldn't purchase enough quad-core T420 models to make it a profitable configuration.

I also wonder if an Optimus-equipped machine could handle it. Many willing to pay for the quad-core might want Optimus as well, and if you can't offer it in an "all-the-toys" version of the T420, why offer it at all?

 

I saw an SATA 6 Gb/s in your system

Would u like to confirm that the T420 can fully leverage the SATA 3 standard ?

 

I think Lenovo would've tested this scenario but the Quad Core under stress conditions would give the T420 little margin in terms of cooling capacity. As LoneWolf15 mentioned it would be odd offering a Quad Core version on the lowest GPU model and not the Discrete version so I don't think Lenovo will be in a hurry to release such spec anytime soon. But then again rumours of a Quad Core version of an X1 shows there could be hope (though I am puzzled on offering such CPU in a much thinner chassis than the T420).

I bought my i7-2720QM from the HP Parts shop, the part number is "631254-001". Though Shleepy got his from DECTrader based in the US. Along with the CPU you get some alcohol wipes and a small syringe of thermal compound. For some reason the i7-2720QM is actually cheaper than some Dual Core i5's and i7's the last time I checked.

I see no reason why the T420 can't take advantage of SATA III, though it pretty much depends on the drives you choose. These are the speeds I got with the 120GB Intel 510 drive though I think you can go much faster opting for the OCZ Vertex 3's if you don't mind tweaking the OS to get it stable.

 

I think we'll be more likely to see quad-core as an option in a T4x-class notebook when Ivy Bridge comes out, especially if the power consumption drops the 40-50% (cpu only, not whole system) that they claim with their new 22nm process and Tri-Gate technology transistors.

The chips may also be compatible with the T420, although Intel's upgraded chipsets for IB should also support USB 3.0 and Thunderbolt.

Either way though, I really wonder how many people truly need quad-core in their notebook vs. just a want. Maxing out my 2520M takes work, and doesn't happen for long periods with my type of use, and 2-cores/4-threads is more than enough for my mobile needs.