ASUS G750JY... a slap in the face to G751 owners?

[Richdog]

I mean seriously, ASUS are bringing out a new version of an old and classic design with a 980M, that I am sure they are aware people prefer (otherwise logially why release an old design?) due to the sleek back design and white keyboard keys that are easier to see and read? Can they have any more contempt for their customers, ie: G51 owners? Absolutely bizarre. :confused:

Info here http://www.asus.com/Notebooks_Ultrabooks/G750JY/

So yeah, I am now really annoyed as I would have loved to buy a laptop with that design and the G751 specification...

[xamoel]

I just took my 751JY to a 10h lan party with non stop gaming, crysis 3, coh2 etc. It never got loud, I barely could hear it at all, and not hot anywhere.
Except for the sound problem it's a perfect buy, I love it!

[ldelczeg]

Enjoy it then.

[kanecvr]

@NitroX - have a look here: https://www.youtube.com/watch?v=nN4GIx-INNs

Temps on both G751 and G750 are too close to tell. The cooling sistem is poorly designed because it recirculates warm air instead of sucking in cold air from the top or bottom of the fan.

Above you have a video of a friend's G751JY-T7068D running Heaven with the palmrest off. That way, the fans suck in cold air from the top. After 30 mins, GPU temps hover around 59-60 as opposed to 75-76C, and CPU temps never pass 70-71C. With the palmrest on, the GPU goes as high as 85C!

There is nothing wrong with the heatpipes in any of these machines - the design is fine - the problem is ASUS did not cut air holes at the bottom of the machine, right behind each fan. If it would have, cooling performance would have increased significantly.

The absolute BEST solution would have been to cut out air holes at the TOP of the machine, in the palmrest above the keyboard, and move the keyboard down 1-1,5cm to accommodate said vents.

[hmscott]

kanecvr wrote:
@NitroX - have a look here: https://www.youtube.com/watch?v=nN4GIx-INNs

Temps on both G751 and G750 are too close to tell. The cooling sistem is poorly designed because it recirculates warm air instead of sucking in cold air from the top or bottom of the fan.

Above you have a video of a friend's G751JY-T7068D running Heaven with the palmrest off. That way, the fans suck in cold air from the top. After 30 mins, GPU temps hover around 59-60 as opposed to 75-76C, and CPU temps never pass 70-71C. With the palmrest on, the GPU goes as high as 85C!

There is nothing wrong with the heatpipes in any of these machines - the design is fine - the problem is ASUS did not cut air holes at the bottom of the machine, right behind each fan. If it would have, cooling performance would have increased significantly.

The absolute BEST solution would have been to cut out air holes at the TOP of the machine, in the palmrest above the keyboard, and move the keyboard down 1-1,5cm to accommodate said vents.

kanecvr, with the top off there is a new cooling component, the heat dissipation into the open air from the heat to rising off the motherboard into open air. That makes the cooling system look more efficient, because it's heat dissipation task is greatly reduced.

You need to dissipate the heat generated by all the motherboard components, not only the closed heatpipe cooling system(s). Removing that task from the cooling load on the cooling system and yes it will appear to run cooler, because it isn't doing the whole cooling task any longer.

The exhaust fans are what draw the air over the motherboard from the bottom vents to cool the entire system. The air comes in cool and is heated up by the motherboard components including the exposed heatsinks and heatpipes on it's way through to the heat exchanger connected to the exhaust fans, and that heat is exhausted through the fans out the exhaust ports. That air is hotter going into the transfer point because it is preheated by cooling the laptop as it comes in over the motherboard; it needs to do that as part of the overall cooling of the laptop components.

If you cut holes in the bottom/top to allow cool air in to cool the heatpipes drawing heat from the heatsinks you are going to allow the rest of the motherboard to heat up - components that aren't monitored for temperature.

What is happening is you aren't cooling the rest of the laptop, only the sealed heatsink/heatpipe portion. That focuses the cooling onto those monitored components but ignores the heat load that needs to be dissipated from the rest of the laptop. It looks better, but in effect is doing much less work, work that needs to be done.

You would need to add fan(s) capacity to draw air over the motherboard to do that portion of the cooling you stopped by cutting intake holes for the heatpipe exchange exhaust as it exists in order to do all the cooling required.

Or, run with the top off 🙂

[NitroX]

@kavecvr: Looks weird as hell without the top cover :)).

@Hmscott: It's not quite like that (or maybe I didn't fully understand what you said). I mean, it's quite legit what Kanecvr said. If they would have made like a few more holes, or even larger ones, right above the fans so they could suck more fresh air and make a better air recirculation inside the case, then all the components would be better cooled. These being said, I also would like to know where are the orifices from where the vents take fresh air. I know that on the G75 they were right behind the display because they could be seen but I can't seem to find the holes on the G751. Did you guys see those holes until now?

Aaand as a proof that the case needs more fresh air under heavy load, I made another test with AC Unity. I kept the game running for 5 consecutive hours, 4 of them being actually gameplay and 1 hour of idle while I've done some other stuff around the house. What I've changed was the ambiental temperature. I kept my room window open and the ambiental temperature was around 20C+/- 2C . This is what my thermometer showed but it was quite cool in the room and there was a constant cool air flow from the window through the door.
The fresh air and lower ambiental temp resulted in quite lower temps (see pics below). Not as low as the old G75 which would have stopped at 72-73C for the CPU, but it is a momentary solution for the winter. I will also try to undervolt the CPU with Hmscott's method and I will also make a test with a 80mm PC fan blowing fresh air beneath the laptop and on the rear exhaust with hopes of improving the recirculation of fresh air. I'll be back with the results.
PS: I'm trying this methods just to find out if it would be worth buying a cooler pad.

[hmscott]

NitroX wrote:
@kavecvr: Looks weird as hell without the top cover :)).

@Hmscott: It's not quite like that (or maybe I didn't fully understand what you said). I mean, it's quite legit what Kanecvr said. If they would have made like a few more holes, or even larger ones, right above the fans so they could suck more fresh air and make a better air recirculation inside the case, then all the components would be better cooled. These being said, I also would like to know where are the orifices from where the vents take fresh air. I know that on the G75 they were right behind the display because they could be seen but I can't seem to find the holes on the G751. Did you guys see those holes until now?

Aaand as a proof that the case needs more fresh air under heavy load.

NitroX, I am agreeing that allowing coolest air in to the heat transfer exhaust fans will reduce temps of CPU/GPU, but what you are missing is that the rest of the laptop components generate heat too.

The existing fans can only pull in so much air, if you reduce the airflow into the bottom vents by diverting suction through taking in air directly under/over the fans, there is not enough air flow over the motherboard - those components aren't going to get cooled off and heat will build up.

So yes, the laptop needs more fresh air under heavy load, but you would need to add suction sources by adding fan capacity for pulling air in through the bottom vents to cool the other components not dissipating their heat through the heatpipes/heatsinks.

In a desktop case fans cooling the computer components by drawing air in front to back over the motherboard and other components. If those fans are redirected and only cool the sealed radiator of the CPU/GPU water cooling system, the rest of the motherboard/case components are going to overheat.

When you take out the radiator / fan cooling system from the computer case to remove heat from the box and make the cooling independent and more efficient, you still need case fans running to cool the rest of the motherboard components.

The laptop is the same system. When you separate the heatsink/heatpipe heat transfer section to take in air directly you cut off the air flow over the rest of the laptop components.

A cooling pad won't help much if at all. All it does is blow air up into the bottom of the laptop, and the G750/G751 are sealed except for the bottom vents, which are already tuned to the maximum capacity of the intake/exhaust fans. You would need to push chilled air, not ambient air, in to the vent in order to make a difference.

[kanecvr]

@hmscott - look mate, I run a boutique laptop repair shop - we do everything from cleaning these things to IR BGA reballing, so I know what I'm talking about. The design of the G750 and G751's casings is FAULTY. I get lots of machines with a damaged GPU / Northbridge with simillary designed cooling systems - i.e. no way to suck fresh air it, fan keeps recirculating warm air over the heat-sink. To fix this manufacturing defect, I take a special tool and CUT a hole at the bottom of the case, directly under the fan, and apply a hard mesh dust filter. This is done on machines with no warranty, that underwent reballing. Now I doubt a G750 or 751 will need reballing since temps don't go up as high as on some laptops, as well as the fact that new CPUs and GPUs will throttle to keep temps down and avid damaging the BGA array...

What other components are you talking about? The PCH is passively cooled, there's nothing on top of it, and it doesn't come in contact with the keyboard either (would have been a good idea to put a thick thermal pad on top so it would dissipate heat into the palmrest) so it's not cooling that. The northbridge is built into the CPU - the VRMs are covered by the CPU / GPU heatsinks, and other components don't require cooling - so - I say again - what other components are you talking about?

If my mate comes over with his G751, I could rerun the test and point my IR thermometer at it, just to prove that everything is cooler with the palmrest off, but I doubt he'll let me take his machine apart again for no real reason, so I'm stepping down from this discussion. You can belive whatever you want - I know I'm right, since all the machines I've modded haven't broken down since.

[CoryBee]

I am still waiting to get my G751-JY. As soon as I do though, I will be performing a mod to add my Astro A50 headset receiver.

While I take it apart I wouldn't mind pointing my IR Thermometer Camera at it.

Cheers

[hmscott]

kanecvr wrote:
@hmscott - look mate, I run a boutique laptop repair shop - we do everything from cleaning these things to IR BGA reballing, so I know what I'm talking about. The design of the G750 and G751's casings is FAULTY. I get lots of machines with a damaged GPU / Northbridge with simillary designed cooling systems - i.e. no way to suck fresh air it, fan keeps recirculating warm air over the heat-sink. To fix this manufacturing defect, I take a special tool and CUT a hole at the bottom of the case, directly under the fan, and apply a hard mesh dust filter. This is done on machines with no warranty, that underwent reballing. Now I doubt a G750 or 751 will need reballing since temps don't go up as high as on some laptops, as well as the fact that new CPUs and GPUs will throttle to keep temps down and avid damaging the BGA array...

What other components are you talking about? The PCH is passively cooled, there's nothing on top of it, and it doesn't come in contact with the keyboard either (would have been a good idea to put a thick thermal pad on top so it would dissipate heat into the palmrest) so it's not cooling that. The northbridge is built into the CPU - the VRMs are covered by the CPU / GPU heatsinks, and other components don't require cooling - so - I say again - what other components are you talking about?

If my mate comes over with his G751, I could rerun the test and point my IR thermometer at it, just to prove that everything is cooler with the palmrest off, but I doubt he'll let me take his machine apart again for no real reason, so I'm stepping down from this discussion. You can belive whatever you want - I know I'm right, since all the machines I've modded haven't broken down since.

kanecvr, I am not saying your observations are invalid, I am saying you aren't considering the whole system, just the closed heatsink/heatpipe heat exchanger in the exhaust fans.

You aren't "recirculating" hot air, you are drawing cool air in to the laptop on a single pass through the laptop, cooling parts - exchanging their heat into that incoming air - which heats it up - that is the hot air you are referring to that is finally used in the heat exchanger.

That heat in that air that finally reaches the heat exchanger is heat that needs to be dissipated. If you cut off that initial pass through the laptop you are stopping the cooling of those components.

Not everything is under the heatsinks.

You have a good idea getting cool air directly to the heat exchanger, but the rest of the laptop needs that initial pass over the components to cool them too.

You can do what you are suggesting, but you then need to provide another source for pulling in cool air over the rest of the laptop.

You can't shoot an IR Thermometer at a closed laptop, and that is what you would need to do to see the components that are closed up, not getting air flow over them, and heating up with nowhere for their heat to go except to continue to build in them and whatever they can conduct their heat through.

If you shoot an IR Thermometer at the open laptop, those same parts are going to be able to exchange their heat with the open air. There may still be a part or two that remains hot even with the open air available, but you are missing the overall picture with the top off venting the heat into the open air.

You may get a better view if you push the top on, leave it running for a while, then quickly pop the top to get a reading for 1 section at a time - it will all quickly cool down as soon as the top is removed and the heat is vented.

Asus spent a lot of time moving from open air flow, with intake from many areas, to a sealed laptop sides/top, with only the bottom vent holes open, to get the desired focused air flow - concentrating the suction of the fans more efficiently - instead of sucking air in from all directions aimlessly. It isn't a bad design, it is an optimal design that efficiently uses the directed air flow through the laptop for cooling quietly.

The reason you get better temperatures for the GPU/CPU is because you have stopped cooling the other components in the laptop, and focused the air flow only through the heat exchanger in the Exhaust fans which only cools the components touched by the heatsinks.

[NitroX]

@Hmscott & @Kanecvr: This could be a long discussion because the real truth is somewhere in the middle. We should stick pursuing the main target, on how to lower the temps of the laptop instead of debating on how the system should have been designed. I'm part agreeing with Kanecvr because the case does need a better air recirculation and I'm also part agreeing with Hmscott because maybe the engineers from ASUS did take into consideration the intake of cool air using the available holes/orifices. And as a proof for what you both say, there is a another thread started by ExpatGamer in which he used an application "Notebook Fan Control" to raise the fans RPM. You can see his results here: http://rog.asus.com/forum/showthread.php?55539-G751-Fan-Control-and-Overheating . Hmscott already saw the thread and knows what I'm talking about. What he proved is that the case needs a better air recirculation and that the system is capable of offering it by raising the RPM of the vents. So you both were right in what you stated: the system needs more fresh air and the cooling system is capable of offering it.

Also yesterday I spent my entire day testing the Undervolting method using Intel XTU which I've seen at Hmscott. The results were positive and the temps are 5-6C lower now with a -90mv on both Dynamic and Proc. Cache voltages. You can see more details here: http://rog.asus.com/forum/showthread.php?52467-Got-your-new-G751JY-G751JT-G751JM-Post-your-review-te... .
This undervolting combined with a higher RPM of the vents and maybe a repaste from the Warranty service, will bring this machine to the temps which we have been used to see in older ASUS G series models.

EDIT: @Hmscott: I have a question for you. During the Undervolting process I saw that for the Manual tuning we also have the ability to lower the voltages on the next slides:
1) Processor Digital I/O voltage offset
2) Processor Analog I/O voltage offset
3) System Agent voltage offset
I don't wanna change these values without knowing what the result may be. Do you have any ideas about them ?
See pics: