Haswell mobile quad memory upgrade 12GB (4GB+8GB) vs 8GB (4GB+4GB)

Have mentioned this before, but never actually experienced it, to test and know for sure. Which I believe once at 12GB will be using Intel Flex mode.

I am buying a G501 that is the model with just 4GB soldered on-board. Basically one dimm slot isn't there but is in the form of soldered on-board, the other is physical, so in theory just 2 dimms. There are many other laptop make/models out there that do the same. I have no option to replace only just one module.

Out of box Asus have just jammed in a single 4GB sodimm module, which gives perfect 8GB dual channel. All good no problems with synchronous dual channel, 8GB (4GB+4GB), no performance loss.

Although I would like to max out the RAM, which going on availability then single 8GB sodimm is the only upgrade to be allowed, which will only allow asynchronous dual channel, 12GB (4GB+8GB), likely performance issues.

Questions are.

1. Is it worth even spending extra on 8GB module only to be able to get a 4GB more from what I already would have, taking a performance hit.
2. If the whole 4GB form first model and then only 4GB from second module is used in dual channel, leaving 4GB in single channel, is going to degrade performance by much or cause strange behavior such a slowness while the IMC tries to work differently/harder?
3. Will the Intel integrated GPU suffer and not get 25.6 GB/s bandwidth, if reserved memory at the end of address range, or is shifted to the range in the single zone.
4. If the last 4GB is single channel, is this going to affect things such as virtual machines performance?
5. In general wonder if dual channel complete with less RAM is better than mixed dual/single channel with more RAM.?

 

From what I know of dual channel ram, nothing should happen if you don't have dual channel. The performance loss is negligible for normal uses. Question 3 is valid though I have no idea what happens, but otherwise I think it should work fine, laptops can be bought with 12 gigs of RAM.

 

Yes, anything that gets relegated to the last 4 GB will run in single channel mode, but hardware is the first thing that gets memory reserved for it, so I don't see how the IGP would be relegated to the last 4 GB in single channel since it'll get its RAM even before Windows is started.

Honestly, below 16 GB, I'd take more RAM over slightly faster RAM.

 

I've got 12GB in my Dell E7440 and have never noticed any slowdown due to the asymmetric RAM configuration. Most of the time 8GB is more than enough for my needs but the extra RAM is there for those occasions when I'm running something that needs more RAM. Even though I have an SSD, it is much, much slower than RAM.

WEI, FWIW, is showing subscores of 6.6 for both the graphics components (Intel GPU) and 7.6 for the RAM.

John

 

Get 8GB. You're better off with 12GB than 8GB, absolutely. But the G501 specs indicate 8GB of onboard RAM, not 4GB: https://www.asus.com/us/Notebooks_Ultrabooks/G501JW/specifications/ as do the numerous reviews I've quickly perused. The GPU has 4GB RAM, not the system.

Not only that, frequently onboard RAM is configured so that it still runs in dual channel. Not sure if this is the case for this laptop though.