ldelczeg wrote:
... 1.28 v module is not the same as 1.35 v module as not the 1.5 v module. In every details i agree with you.
ldelczeg, it turns out the range of acceptable voltage for DDR3-L allows for as low as 1.28v, and Asus shipped some models with that memory, not cheap and hard to find outside of Asus, I know I looked 🙂
The 1.35v is the standard available, but if you can find the 1.28v it generates even less heat. JEDEC standard 1.35V(1.28V~1.45V)
ldelczeg wrote:
hmscott, i downclocked the iGPU in my Clevo, after that the laptop became whisper silent and less times starts the fan blowing. the change is that the maximum iGPU clock changed from 1300 to 800. Software-s under windows reports different clocks as i did the change in the bios of the laptop. The fan starts blowing around 60 degrees celsius.
Now is more times under it, when it is under the cooling is passive.
16x50Mhz=800 Mhz. HOwever i noticed i have 1.5 V memory modules so now i am looking for change them to 1.35 V one or 1.25 V one. If someone could point me to a pair of 1.25 V memory module 2x4gb or 2x8gb one would be nice.
ldelczeg, you have gone too far the other direction 🙂
The DDR3U spec is 1.25v, the DDR3L spec is JEDEC standard 1.35V (1.28V~1.45V)
And, now I find it was early CPU-Z versions that displayed the G750JH Hyundai parts as 1.28v, but has now been changed to read 1.35v.
I just verified by downloading the v1.64 zipped version of CPU-Z, it shows 1.28v, but the latest 1.70.0 shows 1.35v on the same G750JH with the same memory.
Here is my G750JH showing 1.28v part, and later as a 1.35v part:
And, here it is showing 1.28v right now using a downloaded 1.64 version of the zipped generic CPU-Z
Same laptop, same parts 🙂
When you add memory keep the make/model the same, for highest compatibility. Using CPU-Z as above you can find the make/model.
Getting the same 8GB part was easy, ebay had lots of listings for memory pulls - pre-tested burned in memory - for less than new.
For those with 4GB memory that want to add 8GB SO-DIMM's to the user accessible SODIMM sockets, you find the make/model line specification sheet that shows all the parts in the same family, and order the 8GB sister part, that will be most compatible as well.
If you want to get fancy, and not spend too much more memory, you can replace all 4 SODIMM's with 2133mhz parts, and G.skill offers parts that run at full speed in the G750, and I assume the G751 - but no reports yet.
G750 Haswell Boards Support 2133MHz SODIMM's
http://rog.asus.com/forum/showthread.php?47957-G750-Haswell-Boards-Support-2133MHz-SODIMM-s&p=406625...
For me it doesn't offer enough of a measurable improvement, let alone a change I would feel, to justify swapping 32GB of 1600mhz memory that is working great, and then go through all the trouble to pull apart my G750JH to get at the top SODIMM sockets. The G751 seems to be easier to disassemble, but I have only seen photo's, noone has posted a disassembly video yet.
If you find DDR3U 1.25v memory and want to try it, make sure you can return it, it would be fun to see if it works and causes a drop in CPU temperature - and if it is stable, After all it is only .03v outside JEDEC DDR3L spec 🙂
Kingston has a brief description of DDR3U memory as compared to DDR3L, but there is no date (2011?) on the mention, and Kingston still isn't listing DDR3U memory, that I could find:
Ultra Low Voltage DDR3 (DDR3U)
http://www.kingston.com/us/community/articledetail/articleid/9?Article-Title=Ultra-Low-Voltage-DDR3-...
Hynix has developed DDR3U(Ultra Low Voltage) product with 44nm technology.
http://www.hynix.co.kr/mail/newsletter_2010_06/eng/sub01.html
Please come back and let us know what you got and how it works!
Probably optimal to post memory questions and answers here in the G751/G771/G551 sticky:
1.35V memory required in G751/G771/G551s (same as G750)
http://rog.asus.com/forum/showthread.php?53752-1-35V-memory-required-in-G751-G771-G551s-%28same-as-G...
And for G750's in their sticky here:
Upgraders: 1.35V memory is required!
http://rog.asus.com/forum/showthread.php?33744-Upgraders-1-35V-memory-is-required!
Hmm, apart from the Optimus, I really think that the G750 will still be more reliable than G751. I had one G751JY model that I have exchanged due to some backlight bleeding of the screen and a bad enter key. Now, this new models is a 10+ at aspect, but I get some crazy temps for the CPU :|... I don't really know what the issue is but hitting the 90's while playing AC Unity isn't quite recomforting. See the picture below
On the other model I could even OC the GPU with +135Mhz Core and a 5700Mhz Memory and would still have lower temps. I do hope that this is due to a bad pasting and that I will be able to ask the guys from the service to reapply the thermal paste on both GPU and CPU.
EDIT: I also have a problem now with overclocking the GPU. It seems that the OC is locked and I can't change either the Core or the Memory frequencies. I hope this is just due to the new Nvidia driver 347.09
EDIT2: Yes, the locked frequencies were due to the latest driver 347.09. Be careful if you update to this driver!
These are the results after a 2h 30mins gaming session:
On the other model I could even OC the GPU with +135Mhz Core and a 5700Mhz Memory and would still have lower temps. I do hope that this is due to a bad pasting and that I will be able to ask the guys from the service to reapply the thermal paste on both GPU and CPU.
EDIT: I also have a problem now with overclocking the GPU. It seems that the OC is locked and I can't change either the Core or the Memory frequencies. I hope this is just due to the new Nvidia driver 347.09
EDIT2: Yes, the locked frequencies were due to the latest driver 347.09. Be careful if you update to this driver!
These are the results after a 2h 30mins gaming session:
NitroX wrote:
...On the other model I could even OC the GPU with +135Mhz Core and a 5700Mhz Memory and would still have lower temps. I do hope that this is due to a bad pasting and that I will be able to ask the guys from the service to reapply the thermal paste on both GPU and CPU.
EDIT: I also have a problem now with overclocking the GPU. It seems that the OC is locked and I can't change either the Core or the Memory frequencies. I hope this is just due to the new Nvidia driver 347.09
EDIT2: Yes, the locked frequencies were due to the latest driver 347.09. Be careful if you update to this driver!
NitroX, are you running the 347.09 BETA or the 347.09 WHQL? Here is the WHQL if you haven't seen it:
http://www.guru3d.com/files-details/geforce-347-09-beta-driver-download.html
Asus GPU Tweak for Graphics Cards 2.7.1.8 is OC'ing fine for me with the 347.09 WHQL release, on a G750JH
Asus GPU Tweak for Graphics Cards, currently at release V2.7.1.8 for the G750JW/JX/JH and G751JT/JY
http://support.asus.com/download.aspx?SLanguage=en&p=9&m=ASUS%20GPU%20Tweak%20for%20Graphics%20cards...
kanecvr wrote:
...Cooling system is just a mediocre on both the G750 and G751 variants. The 751 has larger heatsinks and shorter heatpipes witch should equal better cooling performance, but ASUS didn't cut out air holes at the bottom of the machine so it loses 20% of it's eficiency. I have a vid showing the G751 with no palmrest - it does 59-60C MAX in unigine heaven over a 30 minute run - versus 70-75C with palmrest on.
kanecvr, actually the G750 series has a better cooling system, as we have found by benchmarking / stress testing both the G751 and the G750.
The G751JY has a combined heat transfer plate between the CPU and GPU heatpipes, and under heavy CPU/GPU load it can thermal throttle the CPU - this is due to the smaller cooling system being combined into 1 such that the heat from both CPU/GPU mix and drive up the heat on both.
The G750 has 2 classes of cooling. the G750JW/JX//JM/JS have smaller heatsinks / fans, and the JH/JZ/JY having the largest heatsinks, heat pipes, and fans. Both systems are independent for CPU and GPU, with no heat transfer connection between them. This helps keep both cool under simultaneous load.
Here are some images, first the G751JM, then the G751JY, and then the G750JX and G750JZ
G751JM
G751JY
G750JX
G750JZ
I wouldn't classify either the G751 or G750 cooling systems as mediocre, but the G750 - especially the JY/JZ/JH are quite beefy, and more than adequate 🙂
@hmscott: I've used both the BETA and the WHQL versions. Both left me with a locked Core clock and Memory Clock. The 344.75 WHQL version still works fine. I'll stick with it for the moment.
@Kanecvr: I have only a single 8GB card which came preinstalled with the laptop. I don't know if it is a 1.35v or 1.5v because Aida64 doesn't seem to give me this information (See the pic below). I'm truly disappointed with G751's cooling... it's not that I'm asking too much, but the G75 I previously had was never hitting 85C even with an OC'ed GPU. This one is good for baking eggs with normal clocks while gaming.... I know that the fans are working, and the copper heatsink could do better but the heat is just not evacuated as fast as it should be. I also think that the pasting job isn't that great since the last model I had was hitting better temps (like -5/6 C compared to the current one).
Even if changing the DRAM would improve the cooling, I can't do that since I don't have another DRAM module and I also don't want to void the warranty . I'm thinking of buying a coolpad but this is just freaking lame when you talk about a 4kg machine that isn't capable of cooling itself... The cooling capacity was one of my most important criteria when I've chosen this laptop, because the G75VW I had was damn COOL.
EDIT2: @Kavecvr: I found out from CPU-Z that the Samsung 8GB module that I have is indeed 1.35v. So the voltage isn't the problem.
EDIT: @ Hmscott: I have seen these pics in another topic and it made me think at something. If the heatpipes of the CPU and GPU are combined, then why is the CPU constantly 10C hotter than the GPU? From my knowledge, the heat transfer usually has the direction (Hotter--->Colder), this means that a part of the heat generated by the CPU should be driven to the GPU. But for this model is the other way arround. If I OC the GPU then the CPU would also run hotter O_o... Where's the freaking logic in their cooling system?
@Kanecvr: I have only a single 8GB card which came preinstalled with the laptop. I don't know if it is a 1.35v or 1.5v because Aida64 doesn't seem to give me this information (See the pic below). I'm truly disappointed with G751's cooling... it's not that I'm asking too much, but the G75 I previously had was never hitting 85C even with an OC'ed GPU. This one is good for baking eggs with normal clocks while gaming.... I know that the fans are working, and the copper heatsink could do better but the heat is just not evacuated as fast as it should be. I also think that the pasting job isn't that great since the last model I had was hitting better temps (like -5/6 C compared to the current one).
Even if changing the DRAM would improve the cooling, I can't do that since I don't have another DRAM module and I also don't want to void the warranty . I'm thinking of buying a coolpad but this is just freaking lame when you talk about a 4kg machine that isn't capable of cooling itself... The cooling capacity was one of my most important criteria when I've chosen this laptop, because the G75VW I had was damn COOL.
EDIT2: @Kavecvr: I found out from CPU-Z that the Samsung 8GB module that I have is indeed 1.35v. So the voltage isn't the problem.
EDIT: @ Hmscott: I have seen these pics in another topic and it made me think at something. If the heatpipes of the CPU and GPU are combined, then why is the CPU constantly 10C hotter than the GPU? From my knowledge, the heat transfer usually has the direction (Hotter--->Colder), this means that a part of the heat generated by the CPU should be driven to the GPU. But for this model is the other way arround. If I OC the GPU then the CPU would also run hotter O_o... Where's the freaking logic in their cooling system?
