Missing memory on Elitebook 8740w, even in Memtest86+. WTH?

I have what seems to be a really strange problem on my new 8740w: I have 4GB of RAM, but Memtest86+ is showing only 3952MB, and it also says only 1024KB are being reserved. Basically, 143MB are totally unaccounted for!

Surely HP's built-in pre-boot authentication software/firmware is not residing permanently in memory, let alone taking up way more than the flash chip it comes from? Does anyone know what could be going on here? Does anyone else have this problem?

I should note that I have an i5, but an Elitebook 8740w wouldn't be setting aside memory for integrated graphics, would it? Even if it did, why 143MB?

 

That's normal . . . I have yet to use a system where memory amounts are reported to be the capacity of the modules.

I have 6GB (2GB + 4GB) in my 8740w and it shows 5999MB, and in my ProBook 5310m I have a single 2GB module yet it shows 1976MB. Must be related to the BIOS or something, I don't know.

Even on my self-built desktop, I have 4GB (2x 2GB) but it shows as 4063MB.

 

Your 8740w experience closely matches my own (145MB are missing, including however much Memtest reserves for you), but where is all that memory going? According to lshw in Linux, the BIOS is only 64KB and has a capacity of 3008KB, so that shouldn't be the issue...

The thing is, my own desktop reports 4095MB (out of 4096), and the other megabyte is explicitly accounted for by the 1024KB reserved memory. If you search Google images for "memtest," you'll see that most report only 1MB or less missing, which is accounted for directly by the RsvdMem column. Whenever memory is not accounted for, I've always assumed that it's taken up by integrated graphics, but...in our case, we shouldn't have any, and even if we did, the amount of missing memory is an oddball number.

I don't like having this memory tied up, but what bothers me more is that I don't know what it's being used by. It made me wonder if it had to do with the SYSTEM partition associated with Windows 7. If that were the case, I would not be a very happy camper, since I don't like the idea of some unknown >100MB proprietary program constantly sitting resident in memory, even while I'm running Linux. That just screams rootkit/hypervisor/etc. Update: Thankfully, that's not the case though. I just completely removed that partition along with Win 7 (after imaging to another drive), repartitioned a few times to different filesystems to corrupt whatever's there, and tried again, and the same memory is still being used for God knows what.

 

I have a 8530w and Taskmanager shows only 8092 from 8192 MB installed. The Resourcenmonitor -> memory shows 100 MB reserved for hardware. I assume this area is reserved for the various devices, when they interrupt and the data has to be stored intermediately. Just my guess.

 

Yes, it is probably a valid assumption. I have 71mb reserved out of 8GB (8740w).

 

Thanks - I just checked Resource Monitor myself in Win 7, and it shows 145MB reserved for hardware. That definitely helps narrow things down.

Still, what hardware does the laptop have that's reserving memory like this? Usually integrated graphics are the culprit, but this is a workstation with dedicated graphics, and I can't see what would need 145MB. This is twice what's reserved on Aikimox's machine (though he's using a quad and a different mobo), and even 71MB seems high to me.

Wait - I wonder if memory remapping is disabled by default in the BIOS with no option for enabling it?

 

Memory Remapping feature gives the OS access to all available memory. If disabled it'd only let windows see under 3gb. It should always be enabled for 64pbit systems. Hence no option to turn it off.

We need other dual core owners to confirm the 145mb. This could strongly hint towards the IGP. Also, I wonder if AMT plays some part in this matter...

 

Thanks for the continued help. According to http://support.microsoft.com/kb/929605, a computer with memory remapping should allow Windows (etc.) to use a full 4GB of RAM as long as the mobo's max address space is at least 8GB (and I assume the same applies to 8GB RAM and at least 16GB address space). The way it sounds though, all other hardware devices should be getting remapped to an address space that does not overlap at all with physical RAM. If it's always enabled for 64-bit systems, that means we shouldn't be seeing any hardware reserved memory at all in Resource Monitor...where IGP is the [sole?] exception, since it actually uses system RAM. (Then again, if it's somehow not enabled, then the 1GB video RAM on our Firepro cards should be cutting deeply into addressable RAM too). Anyway, the 145MB applies to both Charles and me, but IGP couldn't explain your 71MB.

I can rule out AMT on my end btw, since my system came without vPro.

Update: Fishing around on the Internet, some people have claimed that they have freed up all their memory for use by going into msconfig.exe, the Boot Tab, Advanced Options, and playing with the Maximum Memory setting. I don't know if this could possibly free up memory that's hardware-mapped even in Memtest and Linux, but it's worth a try...the problem is, the Advanced Options button doesn't work for me, as if it weren't there at all. What luck!

Another update: I got msconfig working (forgot to reset the boot label when I brought my Win 7 partitions back), but the Maximum Memory setting was already unchecked, and fiddling hasn't helped. For the record, it's a bad idea to check the box and set the maximum memory to 0, as I just found out.

 

Nice top about the Resource Monitor. That is nifty.

Regarding Hardware Reserved memory -- mine reads at 145MB. I have an i5 dual-core processor. Mine came with vPro technology (AMT?). I believe it is enabled.

 

ok i just did two tests.

I can't do anymore because i've run out of CPU thermal paste >.>

Though the benches will be posted when i've done the 5000M/720QM battery tests.

620M

Hardware Reserved 147MB
In Use: 1829MB
Modified: 177MB (SSD Memory)
Standby: 992MB
Free: 13198

Total 16239MB
Installed 16384MB

720QM

Hardware Reserved 73MB
In Use: 1879MB
Modified: 175MB (SSD Memory)
Standby: 993MB
Free: 13264

Total 16311MB
Installed 16384MB


940XM

Hardware Reserved 73MB
In Use: 1871MB
Modified: 177MB (SSD Memory)
Standby: 995MB
Free: 13178

Total 16311MB
Installed 16384MB

2MB of my reserved memory is for the Gobi2000 card if those people are wondering, the system loads the firmware of the device into ram

 

@Siorah,

Did you run the tests on a single system?

 

yep, my WD941EA. 620m/720QM

the 940XM was done on the 5000M machine

atm i don't even have the keyboard on the wd lol, i've been cpu swapping so much - it's just connected, but not screwed in.

 

I now doubt the IGP related difference. More likely 2x memory is reserved when a quad core CPU is in, for 2x more memory slots to control.

 

the i7 quads reserve half the ram of the duals.

 

Ooops. Daaammn, someone needs to go to bed...