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PeterCTO
Paper Tape
Posts: 3
Registered: ‎08-18-2012
Location: London
Views: 4,254
Message 1 of 13

Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution?

Hi there,

 

I am after few laptops and Thinkpad W530 tops my list - beating Elitebooks and Precisions in the process. I am after the top spec and a Quad-Core is a must (virtualisation + some heavy development).

 

What makes me worried though is the reported CPU throttling issue of W530 that occurs while laptop runs on battery power (unplugged from AC) only - all the way down to seriously low 1.2Ghz! Happens when the discreet NVIDIA card is on.

 

I can understand physics behind it as there might be not enough output wattage left to drive K1000 (35Watts) or K2000 (45Watts) but those kepler GPUs are still a far cry from 100Watts GTX680 present in some (though some 17inch) laptops with very little throttling happening. New quad core retina Macbook pro with its 45W GT 650M graphics card exhibits no serious throttling issue whatsoever while on battery - proof it can be done. Only as an example though, retina Macbook is no good for me.

 

I wouldn’t mind bit of it say to 2-2.2Ghz still keeping the GPU and full power and active but to throttle the CPU down to some entry level ULV 1.2Ghz I find quite outrageous - as reason to consider laptop in the first place (dashing Elitebooks for instance) is portability and ability to work on the go purely on the battery power (whether battery lasts for 2 hours or for 5 hours would not matter much, hibernate swap the batteries all of this with SSD is less than a minute).

 

1.) Is there a way around this? Forcing 3rd party BIOS and not risking docking station connectivity or some other issues? Some low kernel/system hack I am not aware of? Has Lenovo fix this (or at least leverage it to acceptable levels) by now?

 

2.) Would it happen if I downgrade W530 configuration to 35 Watts NVIDIA 1000K (as opposed to 45 Watts  2000K) and will also up the battery to 9 cell one?

 

3.) Is it present at all when 9 cell battery is used or is it 6 cell battery problem only?

 

4.) If the answers are negative it will render Lenovo W530 unusable for me for some serious work while on battery. Therefore, is this performance throttling issue present in T530 range? I am really after W series (4 dimms, better cooling, kepler etc.) but would sacrifice all that for no throttling while on battery and might consider T530 instead,

 

Thanks in advance for the answers.

 

Guru
Posts: 9,598
Registered: ‎12-26-2009
Location: CA
Views: 4,224
Message 2 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

It depends on the configuration of the cells in the battery pack. Those laptops generally have more cells (like a 12-cell pack), likely wired to allow for such loads at the cost of battery life. AFAIK, the 9-cell will also throttle.

Supposedly, you can use ThrottleStop to counter the throttling, but do so at your own risk and all that jazz. Nevertheless, if you plan to impart such a drain on the battery pack often, expect to replace it within one or two years.

W520: 2960XM, Q2000M @ 1091/1380, 32GB RAM, 500GB&750GB HDD & 500GB SSD, FHD&MB168B+
X61T: L7500, 4GB RAM, 500GB HDD, XGA screen, Ultrabase
W550s: 5600U, K620M at 1164/1281, 16GB RAM, 512GB SSD, 3K touchscreen
X200s: SL9400, 6GB RAM, 64GB SD card, WXGA+ screen
TPT1: 1839-23U
huberth
802.11n
Posts: 539
Registered: ‎07-08-2009
Location: USA
Views: 4,166
Message 3 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

I believe that the Lenovo throttling algorithm is not aware of type of battery, type of CPU or GPU used.

 

 

 

_______________________________________________________________________
W520 4270CTO i7-2820QM Quadro2000M 1920x1080 Display 16GB RAM 2x240GB Intel 510 SSDs (RAID 0) - BIOS 1.42 - PCMark7:4,568
Samsung Series 9 15-inch NP900X4C-A03US - PCMark7: 4674
Guru
Posts: 1,760
Registered: ‎04-20-2008
Location: US
Views: 4,158
Message 4 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

The CPU will not throttle back on battery if the integrated GPU is the only one being used. You can set the program behavior of which GPU to use for a specific program in the NVIDIA control panel. That will enable TurboBoost to be allowed for the CPU and no throttling will occur. This is the same behavior as was previously exhibited on the W520. The HD4000 GPU is quite capable for most graphic applications.


P70 XEON 1505, BIOS 2.29, UHD 4k Display, 64GB non-ECC RAM, M3000M NVIDIA GPU, RAID 1 512GB Samsung 951 PCIe-NVMe SSD x 2, 2x Samsung 850 Pro 1TB SSD. EM7455 WWAN
P1. BIOS 1.19,Xeon Processor, 32GB, PM981 1TB x 2, RAID 1
T470s, 16GB RAM, BIOS 1.10, i7-7500, WQHD display, 512GB PM961 PCIe NVMe SSD
skfurr
Core Memory
Posts: 17
Registered: ‎06-16-2010
Location: Raleigh, NC
Views: 4,155
Message 5 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

I have to ask:

 

Why does throttling happen at all?  I could see that the fan speed should increase as the CPU temperature rises, and that SpeedStep (or whatever the current Intel processors use) should reduce the clock speed when the load is light or idling.

Also,generally the Intel CPUs would drop clock speeds if the cooling isinsufficient and the CPU is on thermal runaway.

 

But the battery SHOULD have enough amperage to run all components at max load... Right?

Guru
Posts: 1,760
Registered: ‎04-20-2008
Location: US
Views: 4,150
Message 6 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

The battery theoretical power draw is 10.8 V, 7.8 A or 84W which is insufficient to run the CPU (45W) and the GPU (45W) plus the ancillary support circuits. The reason CPU throttling can work is that there are specific signals to dynamically control the CPU clocking . There is no such control for the Optimus GPU environment. Limiting the use of the eGPU allows for full TurboBoost mode for the CPU.


P70 XEON 1505, BIOS 2.29, UHD 4k Display, 64GB non-ECC RAM, M3000M NVIDIA GPU, RAID 1 512GB Samsung 951 PCIe-NVMe SSD x 2, 2x Samsung 850 Pro 1TB SSD. EM7455 WWAN
P1. BIOS 1.19,Xeon Processor, 32GB, PM981 1TB x 2, RAID 1
T470s, 16GB RAM, BIOS 1.10, i7-7500, WQHD display, 512GB PM961 PCIe NVMe SSD
skfurr
Core Memory
Posts: 17
Registered: ‎06-16-2010
Location: Raleigh, NC
Views: 4,144
Message 7 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

Okay, I feel stupid now...

 

W = V * A

 

Yeah, that makes sense.  But I thought that the 7.8 A was not maximum current draw from the battery, it is actually 7.8 Ah (amp hours) meaning that at 7.8 A the battery would last for 1 hour,

 

Instead the machine should draw whatever power it needs (to the limit of the battery discharge rate and what the connectors/traces can handle.)  If one needs long life, the power mgmt software can reduce clock speed, screen brightness, etc. to minimize draw from the battery.  Also, if one NEEDS the highest performance then these "power saving" features can be defeated at the expense of run-time.

 

Just curious...

 

Thanks for the info so far though; kudos sent.  Smiley Happy

Guru
Posts: 1,760
Registered: ‎04-20-2008
Location: US
Views: 4,142
Message 8 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

There are current limiting circuits within the battery that will prevent excessive drawdown of the cells. The battery is rated in Wh from a design viewpoint with the latest 9-cell set for 93 Wh. Li-ion batteries do not take kindly to being fully discharged and will exhibit a shortened useful life if subjected to high current draws. One design change that could be made would be to allow the 9-cell battery + the slice battery to be used in parallel to provide for the current draw. Unfortunately, the present design only allows for sequential depletion Smiley Sad  Perhaps in a future update.

 

 


P70 XEON 1505, BIOS 2.29, UHD 4k Display, 64GB non-ECC RAM, M3000M NVIDIA GPU, RAID 1 512GB Samsung 951 PCIe-NVMe SSD x 2, 2x Samsung 850 Pro 1TB SSD. EM7455 WWAN
P1. BIOS 1.19,Xeon Processor, 32GB, PM981 1TB x 2, RAID 1
T470s, 16GB RAM, BIOS 1.10, i7-7500, WQHD display, 512GB PM961 PCIe NVMe SSD
PeterCTO
Paper Tape
Posts: 3
Registered: ‎08-18-2012
Location: London
Views: 4,094
Message 9 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

Supposedly, you can use ThrottleStop to counter the throttling, but do so at your own risk and all that jazz. Nevertheless, if you plan to impart such a drain on the battery pack often, expect to replace it within one or two years.

Thank you for the answer. I do not mind replacing the battery each year. What is a ThrottleStop? Sorry too late to google Smiley Tongue

PeterCTO
Paper Tape
Posts: 3
Registered: ‎08-18-2012
Location: London
Views: 4,089
Message 10 of 13

Re: Lenovo Thinkpad W530 CPU throttling issue while on battery power - few questions or any solution

The CPU will not throttle back on battery if the integrated GPU is the only one being used. You can set the program behavior of which GPU to use for a specific program in the NVIDIA control panel. That will enable TurboBoost to be allowed for the CPU and no throttling will occur. This is the same behavior as was previously exhibited on the W520. The HD4000 GPU is quite capable for most graphic applications.

Yes I am aware of that. Though HD4000 GPU is finaly capable, it hasn't got no PhysX to use plus some heavy parallelism would require/access CUDA therefore NVIDIA GPU would have to be active. I am not fussy about PhysX that much but until intel implements anything that comes remotely close to CUDA it is not good to use. So I need the GPU and do not mind CPU being set down a little (as long as I have my NVIDIA active) but trashing it down to 1.2Ghz is way way off as the entry level 3720Q I am looking on is 2.6Ghz stock that is without any Turboboost active. Problem is not Turboboost being inactive but the basic core clock is cut down by over 50%.

 

1.) Can anyone with W530 try if 2 cores are dissabled (that should be possible in BIOS) which leaves me with 4 threads and with active GPU is throttling still happening while on battery power?

 

2.) Opting for a  top of the range dual core CPU (saving 10W) and also downgrading to K1000 (another 10W), would there still be throttle (battery only and GPU on)?

 

2.) What about T530? Does it apply to it too?

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