Understanding Memory mapping and "Hardware Reserved"

As I am planning to upgrade my RAM, I potentially have bad modules in the system at the moment, and due to the UEFI BIOS I cannot properly test them with memtest86.

But, I have noticed that out of the 8gb I have installed, (4x2gb Vengeance modules 1333Mhz) that the BIOS sees all 8Gb, Windows sees all 8Gb, but Resource Mon and System information state out of the 8 installed, only 3.98 is usable, and the rest is Hardware Reserved.

I understand that windows handles the way VRAM is used too, of which I have 4Gb on my GFX Card so I assume that's why it's reserving the 4Gb. Or am I missing something ?

I will upgrade to 16Gb in 2x8Gb modules, so I assume i'll instantly lose 4Gb for the GFX Card, which leaves me with 12Gb Usable, which is fine by me.

But with all the googling in the world there seems no definitive reasons for Hardware Resevered other than bad modules. Yet windows memory diagnostics shows the RAM is fine.

Any assistance here would be appreciated as I am really confused. And would like to know that the slots are OK and even if the current RAM Modules are failing, i'd rather know. Thank you.

Make sure any onboard graphics are disabled, if you have it, or at the least, that you have a minimal amount of RAM allocated to it.

Also make sure you are running a 64-bit version of Windows.

Have you tried a clean install of Windows? If you have a spare drive, you can disconnect your current drive, put the spare drive in, do a clean install of Windows, and see if that solves the problem. If so, then you'll know what to do. If not, your original install will still be intact.

You can also try HCI Memtest, which runs within Windows, to test for RAM issues.

Make sure any onboard graphics are disabled, if you have it, or at the least, that you have a minimal amount of RAM allocated to it.

 

Also make sure you are running a 64-bit version of Windows.

 

Have you tried a clean install of Windows? If you have a spare drive, you can disconnect your current drive, put the spare drive in, do a clean install of Windows, and see if that solves the problem. If so, then you'll know what to do. If not, your original install will still be intact.

 

You can also try HCI Memtest, which runs within Windows, to test for RAM issues.

Thanks for the reply.

There is no onboard graphics from what I can see, at least there is no option to disable it in the BIOS. Just the Radeon card that I use. There is no option to allocate RAM in the BIOS either, it is UEFI BIOS too, worth mentioning that.

I run Windows 7 Ultimate 64bit

Really not able to cleanly install windows, I have too much on here I need to keep. But the system is stable, just this RAM issue is puzzling.

HCI Memtest only is able to run on free RAM but for that reason I can test that so thank you.

Basically both windows and the BIOS are seeing 8Gb of RAM. So all 4 sticks are being recognised. Now, resmon shows 4gb is Hardware Reserved, so I am trying to assertain is Windows allocates 4gb of Physical RAM to map the 4Gb of VRAM , or 2 sticks are bad and I need to replace them.

Memtest86 is just simply useless with UEFI Bios, so until they fix it, I cannot test all 8Gb.

My only option really is to test it stick by stick by stick, BUT, now this is why this all came about, I recently changed the PSU from a 650W Corsair that was on the way out, lasted 10 years, awesome, to a SeaSonic 620W PSU.

After the change, the PC was fine for a couple of days and then refused to POST, so clearing the CMOS by removing the Battery got it to POST again, but it was erratic. I reseated the RAM, had issues, but eventually I got it stable and it's booting OK and seems to be running OK. Now I am going to change the RAM at Xmas for 16Gb but I was nervous I had a broken slot tbh.

Oh yeah, and I flashed the latest BIOS again, because it may have been corrupt. The PSU calculators I used for my system, all said I need 550W so I am sure 620W was fine.

It's all a bit messy as information about memory mapping for IO devices is hard to understand.

Have you checked this:

"msconfig, boot tab, advanced options, uncheck the maximum memory if it is limited."

Pulled from this link:

https://social.technet.microsoft.com/Forums/en-US/9946daa7-6cc7-4c67-b4db-d9bc03c63ea6/windows-7-hardware-reserved-memory-way-too-much?forum=w7itproperf

As for the UEFI BIOS, does it not have a legacy boot mode you can enable? Most of them do, especially older boards.

Have you checked this:

 

"msconfig, boot tab, advanced options, uncheck the maximum memory if it is limited."

 

Pulled from this link:

https://social.technet.microsoft.com/Forums/en-US/9946daa7-6cc7-4c67-b4db-d9bc03c63ea6/windows-7-hardware-reserved-memory-way-too-much?forum=w7itproperf

 

 

As for the UEFI BIOS, does it not have a legacy boot mode you can enable? Most of them do, especially older boards.

I have tried the max memory option, checked it and put in 8gb then unchecked it, didn't help :(

Now the BIOS legacy mode, that is an option, so if I use that and boot to legacy memtest might work properly ?

If Memtest checks out, I would highly recommend a clean install. You can unplug your current drive, install a different drive (HDD, SSD, new, used, whatever) just for testing purposes, and do a clean install of Windows on it. Your old drive will remain intact. If it's the same problem, then you just unplug your "test drive" with the new install, plug back in your old one, and you're back to square one. That would rule out a big possibility.

Also, are you on the same version of BIOS that worked initially before the PSU swap? If you changed BIOS versions, I would recommend going back to the version that worked initially, at least for testing purposes, just to reduce as many variables as possible. Since the only thing that changed was the PSU, though unlikely, I would look at it as well. Maybe swap it out with a different one if possible.

Thanks guys, I did get it to boot in legacy, and ran memtest86 with the more familiar blue screen.

It still only saw 4Gb, and that passed fine for a few runs.

So yes, my next approach i'll have to test each one individually. WHich I will do today, so hopefully I can find 2 dead modules, and it's not the motherboard.

If it's the motherboard I'll need to isolate the slots, as when I upgrade i'll only have 2 slots in use anyway 2x8gb.

Hopefully they are in dual channel mode, although speccy says im running 8Gb in single channel. something is wrong here.

things have gone from bad to worse, I tested each stick, and found 2 that would boot n be tested by MEMTEST, but then 2 caused the PC to start n shutdown start then shutdown all the time.

I installed the 2 working modules in dual channel mode and it boots OK, and runs with 2 gb free and says only 2 installed. RESMON shows 2 gig hardware reserved.

So I lost 2 gb , maybe the module was dying and just died by moving it,

BIOS still shows 8gb installed with all 4 in place and when I boot that way, I have 6gb hardware reserved, and 2gb free.

PC is on a go slow LOL but I think its time to replace these modules.

Very strange but at least I got to the bottom of it, turns out that bad modules show up as HARDWARE RESERVED , and that the pagefile also seems to make a difference, the size of it I mean.

Anyway, I managed to get some temporary RAM until I can get some decent stuff. 8gb DDR3 1600 , which is running nicely in dual channel and the PC is fast again.

Still 1gb in hardware reserved tbh thats normal I'd guess.

Now If I do upgrade , I will get 2x8gb sticks of Corsair, can I use them with the 2x4gb sticks of Patriot I bought today ? Would be nice if I could.

Timings will be 9 9 9 24 for both and 1600 clock speeds. just different capacities.