Any information on next generation Haswell based Latitudes?

I'm not buying that claim. From what I've seen so far with Ivy and Sandy, you can trweak a 45W quad core to draw very similar power to a 35W dual, so battery life wouldn't be affected that much. I think, the main reason here is the max power draw and its strain on the cooling system. They would have to make more robust cooling solutions for SV CPU's, and that alone would mean extra cost of R&D as well as final product price and also more noisy systems.

None of the above would bother me personally. In fact, the real deal breaker would be the absence of quad core or at least SV dual core with Iris Pro graphics. That brings me to a very tough decision: stay with what I have for another year or buy something bigger and heavier (Precision?)

 

I'm not sure what technique is used there (most likely, it's under-volting), but unless there is some breakthrough in transistor technology, it won't scale.

Going from 45W to 35W is very different from 35W to 28W (for example), even though these are both 22% reductions. Non-linear behavior and non-idealities will begin to show up as you reduce voltage, especially if you get close to threshold voltage.

 

It's way more simple than that. At 5% of the base frequency, the difference between the two in the actual power draw is negligible (at least from my own testing). You can lock any CPU to stay at min frequency which would be enough for most on-the-go tasks. The battery life would be very similar as at 4-6W CPU is no longer the most power hungry component (LCD + storage + RAM + Wifi + etc). Then simply unlock it when plugged in, or better yet, set a different profile and viola - you got the best of both worlds!

 

I doubt that sacrificing productivity is an acceptable tradeoff...there are some tasks where my i5-3427U is already noticeably slower than my i5-560M.

At base frequency, I would probably be more efficient by putting the laptop to sleep then going back to my desk and using my workstation...

 

It depends on the usage profile of course. From what I can see 5% frequency doen't really affect any performance during light office work, which is what I'd do on the go. I don't see myself pushing 100% CPU and GPU when moving around. In fact only a couple of scenarios would require a 100% CPU power (such as complex comutations, video rendering, etc) and none of those would be efficient on dual core CPU(U) anyways. Which brings me to a very simple conclusion - there's absolutely no need to have full power when running of battery. So unless, you provide a specific usage pattern that would require 100% CPU utilization on the go, and yet would demand a long battery life where every minute counts - I'm convinced that you can handle a 45W quad with a couple of profiles (maybe even different affinity settings) to have both the powerhouse level of perfomance when plugged in and great battery life when traveling...

Oh wait, that's what I've been doing with my hp2570p for quite some time now.

 

Depending on what's happening, I might not always be doing light office work on the go (and that's when I feel it might better to remote to my workstation instead). If something comes up, I may need to execute some PowerShell scripts, process log data, open large Visio drawings, have multiple RDP sessions open, or even spin up a VM. Most of this is single-threaded, so a hyper-threading quad core will not do me any good.

In the occasional situation when I'm just replying to email, 5% CPU would probably be sufficient.

 

Except that an 17W dualcore and 35W dualcore have exactly the same voltage tables.

When i upgraded my i5-2520M to i7-2820QM, i noticed no drop in battery life. The voltages of the i7 part are slightly higher above 2.0Ghz. Idle, where the chip is most of the time, the voltages are identical.

 

Not even two 17W dualcore parts have the same voltage tables nowadays.

Take a look at this part of an Anantech Review for Haswell equiped MBA. As far as I know, the same is true for Ivy Bridge parts.

 

Funny, I do all the tasks you have listed on a daily basis from my hp2570p. I have a bunch or RDP sessions open, GNS3, several VMs, Visio, etc and all that is done without a hiccup on the go without even touching 20% CPU usage most of the time. I can do all that at 5% frequency but to avoid potential slowdowns, I only disable turbo boost when doing those tasks on the go. The CPU will never go beyond 2.8ghz instead of 3.5 but I'm still getting a good battery life. Luckily I have 16GB ram to handle all the virtualization needs. With 8GB it would be a problem...

 

20% CPU usage sounds about right...even with a moderate-sized Visio drawing, the integrated graphics begins to struggle and the fan always spins up (even on my E6220, let alone the X1 Carbon Touch and its i5-3427U). If you locked your CPU to 5%, there would definately be problems if the system isn't idle.

I have 4GB...got to love the corporate standard SKU and soldered RAM. I am always running out of memory (90-95% usage is typical)...really wish I had waited for the E7440. Even if it came with 4GB, it's fixable. :thumbsup: