Dell Precision 7540 and 7740 Owner's Thread

Thanks a lot, @Ionising_Radiation .

Basically you are confirming that my original assumption over heat/power drain with dGPU onboard was right.
Even if I don't exactly know if on 7X40 series Dell improve the power efficiency (specially with RTX cards), I think there should be no big difference compared to 7X30 series.

I don't think to need any more GPU power in the short term, but if for any reason things will changes, I think I will probably go for an eGPU over TB adapter (if supported by this platform).

I also tried a battery duration test, and with throttlestop tuned to disable turbo boost (2.4Ghz max), windows in maximum battery saving, wifi enabled and screen brightness ~ 30%, i could reach 4+ hours with light work loads (1-2 VM launched in near idle loads, basic windows task and browsing). Not bad.

 

I would consider a 'light workload' a single Chrome window with less than 10 tabs, and maybe MS Word open.

4 hours on a 97 Whr battery is not great: 97/4 = 25 W—that's five times what a proper idle power draw looks like. With further tweaks, even the hexa- and deca- core i7s and i9s can reach near-ultrabook levels of efficiency, and one can reach ~12-13 hours of battery life.

Not really—I am only referring to this specific implementation of NVIDIA Optimus, in the Precision 7000 notebooks.

Done properly, Optimus should properly shut down the discrete GPU, and power draw must drop below 10 W—1-2 W for the CPU, PCH and RAM, 5 W for up to 4 NVMe drives, and the remaining ~3 W or so for the display at a low brightness.

 

Something similar. I consider light loads as browsing in firefox/chrome with 4-5 tabs, editing something in office (excel, word), AND write some code in different VM without compiling or launch heavy simulation/other power demanding stuff.
Said that, for me an avarage 20W consuption in this kind of scenario is acceptable, yes is not an ultrabook duration level but the available power reserve is of another order of magnitude, since in the tuned condition I've described before, the 7740 still delivery almost the same performance of my old 4c/8t i7 ivy bridge in full power config.

Yeah, but I mean in real world is really difficult to go close to the theoretical condition specially when it concern the develop of a commercial product.
Do you know if the others mobile WS producers do a better jobs on this front (ie Hp with Zbook 17 G6 or Lenovo with P73)? I think that they are all close to the same results.

 

Ok, just another interesting thing.

I can't manage to bypass what throttlestop calls "EDP Other limit" when on battery mode, every current/tdp limits seems to be set OK also by hwinfo, but the cpu is still locked on 40W TDP which translate in a maximum speed of 3.1Ghz under full load. Seems also that the heat dissipation still remain in passive mode even if I setted up 'active mode' in windows energy management advanced options.

Any idea?

 

Can't comment on those as they're very new, but the ZBook 15 G5 lasts more than twice as long as the Precision 7530, out of the box. But then again, I managed to eke out 12 hours of battery life with a very strange tweak.

Open the Dell Power Manager, and check the Thermal Management setting—ideally you want Optimised, or Ultra Performance.

 

Mmh, I didn't even install it. In this case should be the windows default power management to be in command, right?

 

Install it. Some power subsystems in the Precisions need it. Set it to Optimised, then see what happens.

 

Ok, done. Set to Performance or Optimized, same result, cpu stuck at 40W.
On 7530 can you reach max turbo speed even on battery?

 

Definitely not. And I doubt you can expect to hit max turbo speed while unplugged. The EDP Other limit is a firmware level limit that you will not be able to bypass, and it likely governs how quickly the battery is allowed to discharge.

A lot of strange things happening in this and in the 7530 fora: benching while unplugged, benching with Prime 95... Hmm.

 

Ok, so maybe it's a current limitation hardwired in bios to avoid possible damage to the battery during high amperage peaks.

Anyway in my case is only limiting full load capacity to 40W, in normal task the turbo boost reach out the value setted in throttlestop.