240W PSU ID Chip in 330W PSU

[radji 18]

Hmm. I haven't given Alienware enough credit. They might have planned for this. And you're right. The R1 and R2 motherboards are very similar. Wouldn't be surprised if the R2 has the same set of resistors. Muchas garcias boys. This is at least something for me to tell all the unhappy modders. But changing resistors on the motherboard? I'm betting they're the size of a pinhead.

[StamatisX 1066]

On the other hand, I have never experienced something like that and I am pretty sure I exceed 12A combined but I have the other PSU mod...

--UPDATE--

Just run Metro 2033 benchmark maxed out, my amp meters reported 16A combined, 4A from the one and 12A from the other (one PSU is working more than the other due to slightly higher voltage output)

[imsolidstate 113]

Well I guess we have to assume that the power supply current limit is not present on the R2 motherboard, or at least not on the particular rev that StamatisX has.

Unfortunately though this makes the problem even more difficult to solve. The various regulators on the motherboard for all the different voltage rails have feedback through resistors to the PWM regulator and the higher load of the 7970m crossfire / 920XM may be pulling a rail low enough for the regulator to drop out, causing a shutdown. There could also be other current sensors on the board somewhere that we don't know about. Maxim makes some really tiny current sense amplifiers.

My advice to those having this issue would be to try scaling back clocks one at a time to see if they can get around the problem. For example reduce the CPU clock and see if the GPU still causes a failure, then try just reducing GPU clocks. I realize this isn't really a very good solution but the only way to really figure out what is going on is to use some specialized equipment to monitor each rail and find the one that droops. You would need something like a logic analyzer with a front end for each rail to connect it to it's own channel so that you can compare all of the voltage rails and see which one fails first. You have to be able to compare the rails or you won't know which one drops first.

- - - Updated - - -

Wait a minute, forget all that about monitoring the rails. I just realized StamatisX said 16 Amps. That's 320 Watts. On the output side of the adapter. The input side is necessarily higher. That means that he is exceeding what the 330W supply is able to deliver, and he doesn't have that problem because he has effectively a 480W supply.

This correlates to emails that I've received from someone else saying that he noticed the adapter would shutdown, the indicator light would go off and he would have to unplug the adapter to reset it.

It would appear that the 330W supply is not enough for a really maxed out M17x, i.e. 7970m crossfire and 920XM, dual hard drives, etc.

[StamatisX 1066]

Plus if the efficiency of the PSU is about 85% that means that from the wall it's drawing 376W...

[radji 18]

Maybe the resistor circuit for the R1 was a voltage sensing one and not a current sensing one. Like if it were part of the charge system and sensing circuit is there to detect the correct voltage is coming from the PSU and if it wasn't, the system would "switch" to the battery as to not allow the system brown out? But I haven't seen the R1 schematic so you're probably right about the sensing circuit being a current sensing one.

But that would explain why the dual 240W PSU mod is working for StamatisX whereas other users are having shutdown issues with a 330W PSU mod. Kind of surprising the R2 needs more power than the 330W can put out. I wonder why the 330W works fine for the M18x with an XM CPU and dual GPU setup but not for the M17x R2?

[imsolidstate 113]

I wonder why the 330W works fine for the M18x with an XM CPU and dual GPU setup but not for the M17x R2?

I was hoping someone would answer that question. I keep getting emails asking about doing the conversion but if I do that I really need to know what works and what doesn't. What causes the high power consumption with 920XM/7970m crossfire? Or is it something else? It doesn't make sense that my 840QM/6990m crossfire uses about half the power consumption.

[radji 18]

Maybe it's the design Clarksfield XM CPU, that it sucks up more power than it's successors. That, combined with the fact the 7970m or 680m take 100W of power each (max) might just be slightly too much for the 330W PSU to handle.

[Heatshiver 11]

If you had a 920XM and 7970M CF setup, but didn't OC any of them, would the 330W mod still work?

[StamatisX 1066]

if you don't overclock the 920XM yeah the 330W PSU will handle it, but then again what's the point of paying for an unlocked CPU if you don't overclock it, plus the performance of the cards will be butchered from an underpowered CPU... at this point the bottleneck is the CPU not the GPUs so you need all the juice you can get from the CPU in order to be on par with those...

[aarpcard 19]

Just to give some input.

I've been using a dual 480 Watt PSU for over a year. I consistently am able to draw 330-350 Watts from the wall under really heavy loads. The computer shuts down when draw exceeds ~330 Watts for an extended period of time.

I just bought a M18x 330 Watt PSU and did the ID chip tansplant. Everything went well - and functions. Bios sees the PSU as the 240 Watt one.

However when using the 330 Watt PSU, the breaker inside the PSU will trip when I pull around 240 watts from the wall - compared to the 330+ Watts I can pull from the 480 Watt PSU setup before it trips.

Is this a simple matter of the 330 Watt PSU being too weak or do I have something else going on here? Or is my particular 330 Watt PSU bad?

[aarpcard 19]

Just did some more testing. The 330 Watt PSU will trip around 220-240 Watts. I tried using only a single 240 Watt PSU, and I was able to pull 280 watts and it didn't trip . . . starting to think my 330 watt PSU is bad. Can I fix it? Or should I buy a new one?

EDIT Thinking if I can find the breaker in the PSU and bypass it, I might get somewhere. Anyone know where it is? A schematic of this thing would be very useful.

[sangemaru 51]

I'd like to give a little input as a user of 920XM and ONE 7970m on a 150W PSU: The quality of the PSU matters a great deal.

I use a MSI 16F1 platform, and while measuring power draw at the wall while i was experimenting with overclocking, I determined that the stock system pulls around 120W with 920XM + 7970m (including all the other components that needed working). (just prime95). Power draw would increase to about 165W prime95 + furmark stock.

However, a simple overclock to 3.2GHz across all cores would push my power consumption at the wall to over 220W under load when running just prime95.

This means that the CPU by itself may EASILY account for over 150W-160W power draw.

If we assume an average of 100W power draw/card stock (i forgot to mention, I keep my card undervolted to 1.1V), then a simple CPU overclock to 3.2GHz across all cores will push the power draw upwards of 350-360W for 920XM/940XM + 7970m crossfire. So it makes sense that a dual-psu would be needed for this system to actually have a chance to exploit it.

Unfortunately, not overclocking the CPU is too much of a bottleneck, since the old nehalem sometimes bottlenecks even a single card, even massively overclocked.

Now, the point, is this:

I have two PSU's on this system. One Delta rated at 150W (fat one) and one Delta rated at 240W (slim one). The 240W was modded to work with the MSI machine.

I can push the CPU on the 150W to any frequency so long as I don't attempt to do massive overclocks on the 7970m. Something like 900/1300 clocks on GPU with 3.2GHz on CPU will work just fine.

The 240W will trip and shutdown on any GPU overclock, and the CPU may trip if it's above 3.05GHz.

So, PSU quality makes a huge deal of difference. The 240W-rated PSU can barely take 220W. Any higher and it will trip. The 150W PSU however, has been tested for hours under loads of over 250W. It finally tripped at 265W on the wall.

@aarpcard: My 240W PSU used to trip at 150W, but a friend checked it and found areas where, instead of the MOSFETS that should have been there by design, the PSU came from the factory with... resistors. He replaced them with mosfets and power capacity increased to 220W. Maybe you could give it a try. Otherwise, replace it.

I still believe a proper 330W PSU will feed the m17x R2 just fine, providing not too high overclocks on the CPU and a little undervolt on the GPU. If someone gets lucky, even a decent 240W could power it. But nobody should expect this situation to work stock.

[imsolidstate 113]

Ok, sorry to everybody that has been waiting around for a fix for this. I've been busy and haven't had time to dig into it.

I did figure out what is causing the power supply to trip at 240 watts. It's a simple fix, and my PSU put out 440W before shutting down once I fixed it.

See here: 330W power supply for M17x update » imsolidstate

[svl7 5711]

Simply excellent! Thank you very much for sharing.

Got a 330W PSU on the way for my M15x... thanks to your work the hardest part will be to open the PSU That broken 240W I have is a real PITA to open.

[Nospheratu 275]

Thanks for taking the time to resolve this issue @imsolidstate, this is going to help A LOT of people

So I guess its not possible to just mod the 240W ID chip inside our M17x chassis since the ID line will remain high and deliver only 240W. So we have to crack open the 330W to ground the ID line.

Would it still work if I grounded the ID line coming into the chassis? To be more clear, break the ID line connection within the chassis at the power jack and ground the ID line connection coming in from the PSU to drive the line low and enable the higher power output. Then mod the 240W ID chip as you stated below.

@Nospheratu yes you can do that. From the series resistor it's a straight run through to the motherboard. If you wanted to put the ID chip inside the laptop, there are a few locations right by the power jack. There is an inductor that is the first thing the ID signal goes to, that would probably be the best place to do the modification. You need to pull the inductor so that the ID wire no longer goes out to the power supply. Because of the skip ROM command, there can't be any other devices on the bus. Then just solder the data pin of the chip to the EC side of where the inductor was and use two jumper wires to ground the other two pins. That should keep it nice and low out of the way of the CPU heat pipe.

If this is possible I wont have to crack open the PSU.

[imsolidstate 113]

@Nospheratu, yes, I think that would work. As long as the motherboard can read the ID chip and the power supply sees a low level on the ID line, you should be fine.

[Guest]

Ok, sorry to everybody that has been waiting around for a fix for this. I've been busy and haven't had time to dig into it.

I did figure out what is causing the power supply to trip at 240 watts. It's a simple fix, and my PSU put out 440W before shutting down once I fixed it.

See here: 330W power supply for M17x update » imsolidstate

Simply excellent! Thank you very much for sharing.

Got a 330W PSU on the way for my M15x... thanks to your work the hardest part will be to open the PSU That broken 240W I have is a real PITA to open.

Awesome stuff. Nice job!

Now I need to figure out the right way to mate two 330W AC adapters for my M18x R2 to have a 660W PSU. I have two ordered and on their way.

[Guest]

Awesome stuff. Nice job!

Now I need to figure out the right way to mate two 330W AC adapters for my M18x R2 to have a 660W PSU. I have two ordered and on their way.

Worked out fine.

[bigchuk00 13]

so we just need to solder those 2 wires in and thats it? I'm trying to clarify as i have never done a thing like this before but would like to. A video will be nice though, didn'nt understand half of what was written there.

[bagster 10]

I have successfully transplanted the id chip from a delta dell  psu - 240 watt in a delta clevo psu 330 watt - you will also have to transplant the small resistor next to the id chip as well. I have also changed the power jack to fit my awR18x2. Works like a charm but it still reports in bios as being a 240 watt. Does anyone know how to change this... i mean does anyone have a backup of the rom for a 330 watt so that I may reprogram a one wire chip. Thanks!

Edited January 17, 2021 by bagster