S-XPS 1645 AC Power Throttle Issue Investigation

[clogui]

Ah ok,
so let's hope they find the bios update too for the 1747 and ship with a 130w adapter.

[Mitchell2.24v]

Our teams are still looking into this. At this point, I can say that our development team is working on an updated BIOS revision that will address throttling thresholds.

Since you're jere giving out some news, which we all appreciate, could you elaborate on that a bit:

- Which thresholds are you talking about. The ones for 90W or the ones for 130W / 150W? Personally I would not use a bios that throttles even later on a 90W PSU. I would have to bring marshmellows before a gaming session.

- Can you confirm or deny that the total power requirements for the 1645 is greater than 90W? I'm really curious to know what Dells official stand is on that.

- Is there a timeframe for this fix?

If it helps I can post a photo of my 1645 running only FurMark and pulling more than 90W from the wall. A few moments after that my system slows down all the way back to the previous century. There's no need to run other tests at the same time. FurMark (which only loads 1 thread of the i7) on its own can bring my system to its knees (and beyond).

I know some of is are still hoping for a proper fix. Please let us know where you really stand.

[Mitchell2.24v]

OK, in response to my own post above, I redid the simplest test with a Watt meter and took photo's. It takes under five minutes and pretty much proves the 1645 needs more power!

Download ThrottleStop / i7Turbo, RealTemp and FurMark (which only uses a single thread out of the eight threads available).

Start 'm all up, and don't let ThrotleStop change your system. Only use it for monitoring purposes.

In a little over a minute and a half, my system pulls more than 90W:



This is where it starts throttling, down to 25% or even 12.5%.



Even when fully throttled down, my system still manages to pull 95W from the wall. This is in under three minutes from starting FurMark! If you leave this running, your PSU will shut itself down due to overheating, I've had this happen in under thirty minutes, using the stock PSU and no modifications by ThrottleStop.



These tests were done with a brand-new PA-3E adapter, a 1645 and no other software running but FurMark, i7Turbo, RealTemp and ThrottleStop. The 3 utilities were used for monitoring only.



After shutting down FurMark (I don't like to break my PSU) the system still pulls 45W at idle, with the battery full, so no charging needed.



The lowest I've ever seen it go is 32W, with the CPU/GPU idle, screen on its lowest brightness, keyboard backlight off, WiFi off, BlueTooth off. But why buy a machine with all these features if you cannot use them.

The base power usage leaves very little headroom for GPU and CPU, although other tests I've done indicate that using the CPU only (so Prime95, Office work, Photoshop, etc) doesn't tend to lead to throttling most of the time. It is mostly GPU usage that leads to CPU throttling.

So to summarize once again for Dell, this time with visual proof: the 1645 needs more than 90W to fully utilise the onboard hardware, specifically the GPU. For a machine with a powerfull dedicated GPU this makes no sense. Why incorporate a ATI 4670 if it cannot be used.

[daraj]

Another proof for DELL. The above should be added to the first post.

[Lorthirk]

Now I'm wondering: are 130W enough, or should we request higher wattage (150, or even 210)? Could someone with a watt meter and Throttlestop make some test please?

[Daddler]

Can anybody with knowledge of power supply and motherboards please explain how the extra wattage can have consequences for the 1645s hardware, long term?

Is it really a genuine risk of frying the on board hardware by using a higher wattage power supply than the 90w dell includes, or is this just another shot in the dark excuse from dell to avoid having to send out 130w adaptors?

@Mitchell

Thanks for doing the tests! I guess it's beyond any doubt now that our machines really do need alot more power than what the 90w can ever deliver, with or without a BIOS update.

[Mitchell2.24v]

@Mitchell

Thanks for doing the tests! I guess it's beyond any doubt now that our machines really do need alot more power than what the 90w can ever deliver, with or without a BIOS update.

No problem!

I don't have a 130W or 150W brick yet, so I cannot run te same tests with ThrottleStop enabled. But I'm sure there is someone here who has a bigger brick and a Watt meter... Once I get my own big brick, I will re-run the tests.

[Dany|R]

If AC adapter draws 95w at wall, how many watt request tha laptop?
If the AC adapter has an efficient about 80%, 76w is the power that the laptops draws....

Sorry for my "english"

[Mitchell2.24v]

If AC adapter draws 95w at wall, how many watt request tha laptop?
If the AC adapter has an efficient about 80%, 76w is the power that the laptops draws....

I'm not sure how to calculate the power draw at the laptop side. Unfortunately I cannot measure that.

If your method is correct, and the 1645 really does need 90W, it would need at leas a 112,5W power supply. That would be the dumbest mistake ever: to ship the laptop with a power supply that exactly fits its needs, only to forget about its efficiency

But since people are (or were) reporting power draw of over 120W this will probably not be the case.

Anyway, I would still love to hear Dell officially say: The 1645 does/doesn't* need more than our 90W power supply can deliver.

* cross the one that's not relevant.

[HSeldon]

OK, in response to my own post above, I redid the simplest test with a Watt meter and took photo's. It takes under five minutes and pretty much proves the 1645 needs more power!

Download ThrottleStop / i7Turbo, RealTemp and FurMark (which only uses a single thread out of the eight threads available).

Start 'm all up, and don't let ThrotleStop change your system. Only use it for monitoring purposes.

In a little over a minute and a half, my system pulls more than 90W:



This is where it starts throttling, down to 25% or even 12.5%.



Even when fully throttled down, my system still manages to pull 95W from the wall. This is in under three minutes from starting FurMark! If you leave this running, your PSU will shut itself down due to overheating, I've had this happen in under thirty minutes, using the stock PSU and no modifications by ThrottleStop.



These tests were done with a brand-new PA-3E adapter, a 1645 and no other software running but FurMark, i7Turbo, RealTemp and ThrottleStop. The 3 utilities were used for monitoring only.



After shutting down FurMark (I don't like to break my PSU) the system still pulls 45W at idle, with the battery full, so no charging needed.



The lowest I've ever seen it go is 32W, with the CPU/GPU idle, screen on its lowest brightness, keyboard backlight off, WiFi off, BlueTooth off. But why buy a machine with all these features if you cannot use them.

The base power usage leaves very little headroom for GPU and CPU, although other tests I've done indicate that using the CPU only (so Prime95, Office work, Photoshop, etc) doesn't tend to lead to throttling most of the time. It is mostly GPU usage that leads to CPU throttling.

So to summarize once again for Dell, this time with visual proof: the 1645 needs more than 90W to fully utilise the onboard hardware, specifically the GPU. For a machine with a powerfull dedicated GPU this makes no sense. Why incorporate a ATI 4670 if it cannot be used.

What's the power draw of the RGBLED from minimum brightness to max with everthing else the same? Also curious about keyboard brightness? (one of these days I will get my own meter...)