R20/R40plus and power management

Hi,

I bought the R40Plus(which I believe is the same as R20 with bigger screen) as a desktop replacement as well as a MCE/home server(X1250 is good at video and low resolution game that fits well on S-video TV output).

So far I like it very much except in the power management department in the following area:

1. It doesn't enter ACPI C3 state when on AC power
2. It doesn't have BIOS option to setup wake on lan
3. there doesn't seem to have anyway to reduce the power usage of X1250 as I can't find the PowerPlay option in CCC.

While it only means around 8-13W(my rough estimate it uses about 15W at idle) power difference but at 24/7, I would like to reduce the power usage as much as possible(I like the always on convenience but still try to be kind to the environment).

Does anyone know if there is anything that can be done about these issues ?

 

Various points:

1. Yes, I believe that the R40 plus has the same hardware as the R20. If you haven't seen it, you may be interested in my review of the R20 (link below).

2. The R20 draws about 25W from the mains socket when idle with the display at maximum brightness (20W if the display is at minimum brightness).

3. If you go the the Realtek Network card propeties in Device Manager then you may find a Wake on LAN option. It is there on the R20 - see the attached.

4. I noticed that the R20 doesn't enter the C3 state on battery, never mind on mains power. My X60 plus goes into the C3 state when on battery but not when on mains while my Q35 will go into C3 on both mains and batttery. However, the Q35 (with 12.1" display) still draws about 16W from the mains socket when idle.

5. I couldn't find any PowerPlay option on the R20. But I don't have it on my X60 plus with the X1700 (which definitely needs it and should have it). I suggest that you approach Samsung support.

6. You may find you can achieve useful power savings (provided the wake on LAN works) by getting the R40 to go to sleep but not hibernate). The R20's power consumption drops to around 1W when sleeping.

7. I would strongly recommend undervolting the CPU so that you reduce the power consumption and fan activity when the computer is underload. However, undervolting will make no difference to the idle power consumption.

Hope this helps. Let us know how you get on.

John

 

Thanks for the information.

It seems that the power supply is very inefficient based on your measurement. My R40P draws about 14-15W on idle(using battery which can go to C3) and I have read somewhere than C2/C3 difference would be in the at most 1-2W range. So if it draws 20W from the wall, that is quite some waste in the process.

I have already enabled the wake on ARP/PING option in the realtek driver but it doesn't response to etherwake. I have another desktop PC using the same realtek driver with the same setting having no problem wakeup from sleep/suspend. So this still seems to be a BIOS thing.

By undervolt, I assume you mean doing it while under heavy load. I tried to use rmclock but it doesn't allow me to set the voltage, somehow.

The only thing that seems to be buy me a bit more is clockgen which can bring it down to 600Mhz(instead of 800Mhz). However, at this speed, reboot no longer works. I end up having it at a higher clock(700Mhz).

The last thing I want to try would be atitool and underclock X1250 but it failed to recognize the display(I believe some driver issue as I can do it when booting into XP though XP doesn't support dynamic switching as good as Vista which end up using more juice).

I tried to call samsung support but met with some script readers and don't think they know what I am talking about.

The ideal situation is having the wake on lan option enabled in BIOS as that would buy me the most power saving yet always available. Otherwise, seems that I have to stuck with the 20W draw(as by your measurement) which while not too outrageous still contribute 175kwh a year(not sure how much CO2 is that).

 

You have evidently explored the options quite thoroughly.

I have never used the Wake on LAN facility but I just looked in the Q35 BIOS and there is no option there either.

As for PSU efficiency, they are probably less efficient under part load, or maybe Samsung have got the power management on the R40 plus slightly better than the R20 which is a couple of months older.

RMClock: Compare the difference between the two attached pictures. Try clicking on one of the performance state entries and then you can change the voltage. It's not obvious until you have done it. Make sure that the minimum speed voltage is set to 0.95V and then go to the bottom row, click on it and then select a different voltage in the voltage selection box. I just let RMClock interpolate.

I agree that 20W power drain is not good, but it is the same as for the NTL cable TV set top box when on standby or my Freeview STB in another room. I'm waiting for solar panels to come down further in price, but this approach will also need battery storage.

You might also want to further explore tweaking the XP power options. You say that ATItool works with XP. RMclock has its own dynamic switching (I have set it single step transitions and to not step up until the CPU is 75% loaded) while another switching software is SpeedSwitch XP.

You might want to put your Wake on LAN and power problems to Samsung support through their electronic messaging system. That way you don't spend a long time on the phone and if you get an unhelpful answer then you just bounce it back knowing that next time someone else is likely to pick up the message.

John

 

Further thought: What BIOS version do you have?

Someone pointed out that there are some recent new BIOS updates at Samsungpc.com and I see there is an R40plus BIOS 02YE with a comment "Fix system halt on resume". This might cure your ClockGen issue

It's worth a try if you have not already got this version. The Windows BIOS update procedure is simple and seems to be reliable.

John

 

Thanks again for the detail instruction.

My machine is already running the newest BIOS.

I have settled with underclock using clockgen and undervolt, which when running on battery gives me about 12-13W. I can live with the fail to reboot as it is only the POST fail so just shutdown and restart is fine, so long I am in front of the machine.

Too bad it seems that the no C3 on AC is an Intel recommendation and most of the vendors follow it to the T or else I can get a quieter machine when on AC.

As for wake on lan, I believe samsung is targetting home market and don't see the need for it.

Lastly, it seems that quite some subtle changes have happened in Vista which gives an overall better battery life comparing to XP, quite the contrary to what I see on the net about aero glass eat power. It may be the case for dedicated graphic card but definitely not what I see on R20/R40plus. And underclocking the ati chip(to 200Mhz core) while running XP only yield very little power saving for my usage.