P4C800 + 4x1GB = 2943MB POSTed

[jricha34]

I have a seemingly odd issue. I picked up 8x1GB Corsair VS1GB400C3 (Value Select) chips for two machines with P4C800 Deluxe MOBOs. I am working on my "test" machine and have run into a problem where when I put in 4x1GB, 3x1GB, or even 2x1GB + 2x512MB I end up POSTing with 2943MB.

 

I reached 2943MB only after upgrading the BIOS to 1019.002, prior to that my initial reading was 2300MB, then when I came up to 1011 it read like 2700MB. So I downloaded 1019 from the ASUS site (couldn't auto-update to it) and then finally got the 2943MB reading.

 

Memtest-86 shows 2943MB.

 

Microsoft Memory Test shows 4x1GB

 

CPU-Z shows 4x1GB

 

My memory settings are 3-3-3-8.

 

 

Initially ASUS support said that the issue was ICH5 allocations but that doesn't make sense since I don't see even 3GB. So I asked again and now they are saying that it is either because the memory isn't approved for use with the MOBO or I have bad timings or bad memory. I have cycled through all combinations I can think of with the 8 chips in the 4 slots every combination of 2x1024 shows 2048 and every other combination mentioned above shows 2943MB.

 

According to the Corsair site, the RAM is fine for this board. Again, the timings are as the Corsair site lists them.

 

I have seen a couple of posts on other forums of folks putting in 3 or 4GB of RAM and not getting even 3GB even though the board is alleged to support 4GB (with the ICH5 caveat which I expect would pull 500MB or so).

 

Has anyone gotten a P4C800 to show more 3GB or more? Any idea on what could be wrong?

 

thanks, joe

[RAM GUY]

Joe this is a chipset and O.S. limitation. The MB will see a max of 4 Giga Byte 4000 M-Byte not 4096 M-Byte of memory and the memory used for cache will come off the top like for cache on your CPU and memory in your Video card. In addition, what ever you have the AGP aperture size set too will also come off of that number as well.

Example:

4 Giga Bytes = 32,768 M-Bits

Any 32 Bit O.S. or Chipset will only see 32,000 M-Bits

Then it would have to subtract any other memory used in the system like for your Video card and or cache on your CPU, Lan or Modem. That would the total size of memory accessable to your system.

[jricha34]

Thanks, I think I finally worked it all out. Thanks for responding.

 

I ended up disabling everything (all USB, all drives, all everything) except for the VGA card and that I took down to an aperature size of 4MB and got the RAM to POST at 3044. Obviously the machine is worthless at that point but that seems to be the max that board can really display.

 

It is kind of disturbing that they advertise the board as supporting 4GB but obviously the extra 1GB chip does absolutely nothing for you from the MB standpoint. Their support of it is on par with Florida supporting the idea that you can bring snow skis into their state. You can do it, it just has no value.

 

thanks again.

[Wired]

Could always ski down Mt. Dora in Florida! (FL joke: it's the highest point in the state I think, small town that has crapload of arts and craft stores)

[RAManiac]

I have a seemingly odd issue. I picked up 8x1GB Corsair VS1GB400C3 (Value Select) chips for two machines with P4C800 Deluxe MOBOs. I am working on my "test" machine and have run into a problem where when I put in 4x1GB, 3x1GB, or even 2x1GB + 2x512MB I end up POSTing with 2943MB.

 

I reached 2943MB only after upgrading the BIOS to 1019.002, prior to that my initial reading was 2300MB, then when I came up to 1011 it read like 2700MB. So I downloaded 1019 from the ASUS site (couldn't auto-update to it) and then finally got the 2943MB reading.

 

Memtest-86 shows 2943MB.

 

Microsoft Memory Test shows 4x1GB

 

CPU-Z shows 4x1GB

 

My memory settings are 3-3-3-8.

 

 

Initially ASUS support said that the issue was ICH5 allocations but that doesn't make sense since I don't see even 3GB. So I asked again and now they are saying that it is either because the memory isn't approved for use with the MOBO or I have bad timings or bad memory. I have cycled through all combinations I can think of with the 8 chips in the 4 slots every combination of 2x1024 shows 2048 and every other combination mentioned above shows 2943MB.

 

According to the Corsair site, the RAM is fine for this board. Again, the timings are as the Corsair site lists them.

 

I have seen a couple of posts on other forums of folks putting in 3 or 4GB of RAM and not getting even 3GB even though the board is alleged to support 4GB (with the ICH5 caveat which I expect would pull 500MB or so).

 

Has anyone gotten a P4C800 to show more 3GB or more? Any idea on what could be wrong?

 

thanks, joe

 

joe:

 

i had a similar problem with my asus a8n32-sli that i filled with 4 gigs of the same type of corsair valueram that you have -- only 2.9 GB would show up. i fiddled around in the bios and enabled an option that was called something like "memory hole remapping" (can't tell you the exact option b/c my board's at home). a search with my friend google revealed that enabling this option in the BIOS would remap the lost memory that is part of the overhead for ACPI power management, PCI, PCI-E etc. so now, 3.9 GB suddenly were available. it's still not the full 4 gigs, but still better than 2.9 :biggrin: .

 

maybe there's such a BIOS option for your mobo as well. hmm, i haven't searched in the BIOS of my P4C800-E deluxe for this option, yet, because there was never a need, but this is intriguing indeed and i'll definitely check once i'm home.

 

R.

[RAManiac]

oh boy, i can't find this dang "memory hole" option anymore -- not even on my new asus A8N32-SLI! i know i didn't dream it! maybe i've been testing a few too many mobos lately... perhabs someone else is smarter? :o:

 

the BIOS of the A8N32-SLI is indeed reporting 3.9 GB, but memtest confirms 1.4 GB to be reserved ("RSVD").

 

R.

[RAManiac]

whew! i knew i didn't make this up.

 

on my ASUS A8N32-SLI, it can be found by accessing the BIOS and going through the following menu tree:

 

Advanced > CPU Configuration > Memory Setting > Memory Configuration > Hardware Memory Hole [Enabled]

 

description reads as follows: "Enable Software Memory Remapping Around Memory Hole; Note: ONLY supported by Rev E0 Processor and above"

 

R.

[Yellowbeard]

It is kind of disturbing that they advertise the board as supporting 4GB but obviously the extra 1GB chip does absolutely nothing for you from the MB standpoint.

Actually it does if you are running an OS that can handle the extra memory. Not to be a smarta55 but, the MOBO maker cannot presume to know what OS you will run.

 

However, it is not uncommon for the MOBO makers to list every last specification they can to make their product look great and superior to other brands. It's not entirely ethical IMO as barely provide the buyer enough raw non-marketing info to fully understand what they are buying.

 

Mike.

[alansimon]

Hi Specmike,

 

Could you please relate to me your settings for your P4C800-E Deluxe motherboards and your Corsair PC4400 memory?

 

Thanks.

 

Alan Simon

[Yellowbeard]

I have the Vdimm at 2.85v, timings at 2.5,4,4,8, burst length at 8, CPU Performance Mode at Standard, Memory Acceleration Mode at Auto, the CPU is Lock Free enabled and the FSB is at 275mhz. My Vcore is 1.4v.

[Lord Chaos]

You need to enable the the setting above, there's another setting too which should be off, but I can't remember right now. With that I got the full 4 Gb of memory on my ASUS A8N32-SLI Deluxe.

 

Also remember to run a 64 Bit OS or you *WILL* not be able to use all the memory, I use WindowsXP 64 Bit and it gives me all 4 Gbit in windows.

 

Of course, be aware that several programs (especially utilities) aren't compatible with 64 Bit XP, like zonealarm and such and also certain optimizer programs can't figure 4 Gb of memory out and reports the wrong amount.

[tcassisi]

I am on an EVGA 680i motherboard on 32-bit Vista and recently upgraded from 2G to 4G of RAM.

 

The BIOS reports 4G.

 

Vista 32-bit using 'msinfo32.exe' reports:

Total Physical = 2,813.75MB

'winsat features -v' reports:

Same physical

Dedicated video memory = 732.50MB

 

On a normal 32-bit o/s *without* the option to "remap PCI resources above 4G", this means that the "memory hole" is:

 

4096MB - 2813.75MB - 732.50MB

= 549.75MB is unaccounted for.

 

Presumably if I added up *all* the memory ranges within the 'Hardware Resources / Memory" tab of 'msinfo32' it would come to this number.

 

Being lazy, just ignoring old legacy PCI mappings < 1MB (e.g. video used at startup time),, the lowest address is:

 

0xAFF00000 = 2815MB

 

Which almost exactly matches the rounded 2814MB figure.

 

----

 

* Could someone with Vista 32-bit AND this "bios remap option" turned opn repeat the above?

 

* Does anyone know which motherboards/BIOS support this?

 

I am also worried about a further 756MB of RAM being 'lost' when I add in a 2nd GPU in SLI....

 

Anyone seen any drop in available physical RAM when adding a 2nd card?

 

If I was able to use Vista 64-bit, it would simply remap the I/O space to outside of my RAM area, leaving almost the full 4G free (the legacy bit cannot be remapped).

 

Finally, I thought that you had to enable the /PAE boot switch with Vista 32-bit as well as having 'bios memory hole' support in order for this to work?