Strange Problems: 2 x TWINX2048-3200 on Asus P4C800-E Deluxe

Hello everone and especially Ram Guy, i'm currently building a system that is supposed to have 3GB or 4GB of Ram, using an ASUS P4C800-E Deluxe Board (i875 based). I'm therefore using the TWINX2048-3200 Modules, of whom i have bought two pairs (2x2GB = 4GB). However i ran into serious trouble. I first installed two of the Corsair Modules, along with two standard 512MB Infineon PC3200@CL3 DIMMs in the P4C800-E Deluxe Mainboard. That should have resulted in 3GB Ram. (i took care of the dual channel slot distribution as outlined in the manual) However i was shown at bootup only about 2,8 GB of Ram. I suspected a BIOS Problem and updated to the latest version 1016 and did some BIOS configuration. After that i had only 2,0GB of Ram left ! It turned out, that raising the AGP Aperture Size had reduced my available memory to "2047MB" (why not 2048MB I wonder?). I can get a numer of Ram Sizes (2,0GB to 2,8GB) by modifying the AGP Ap. Size between 4MB and 256MB. Other settings (Memory Timings, SPD Settings, Memory Voltage - did not show any effect). I started to wonder and put in all 4 Corsair DIMMs, but no 4GB, only Values between 2,00GB and 2,8XGB were available according to the BIOS (and also according to WinXP, as i later found out). With 2 Corsair Dimms and nothing else i have 2048MB, unless i raise the AGP Aperture Size to the Maximum, then i have 2047MB according to the BIOS. I really wonder - WHAT THE HELL IS GOING ON HERE ?!? Before the P4C800-E Deluxe had arrived, i used three of those Corsair Modules in my nForce2 A7N8X Deluxe (Board Rev 1 with FSB and memory @ 166MHz/333DDR MHz). I just plugged them in, had 3GB of Ram (even @CL2.5 i think due to the lower frequency) and everything was working flawless - despite my large Aparture Size! Can anyone explain what is going on? According to here: [url]http://www.houseofhelp.com/forums/showthread.php?t=24464&highlight=twinx2048[/url] the memory is supposed to be compatible with the Board. I know the limits (only 2GB of Ram in WinXP per Process, unless using the AWE API), something like 3,5-3,8GBGB of Ram in a 4GB System due to PCI Resource Allocation. According to here: [url]http://www.houseofhelp.com/forums/showthread.php?t=24310&highlight=2048mb[/url] someone with a Board that is pretty similar (isn't it?) has good results (good = 3,8GB). Any help is really appreciated! Thanks a lot in advance, Gerald

Hi Ram Guy, thanks for your quick Response. i've been running the PRIME95 Memory Stress Test for 9 hours tonight, and no errors were detected (even at Stock voltage, with the timings you mentioned). I did some additional Research with my 4x1GB Memory Modules in a P4P800 Mainboard (i865PE based) of a friend. Even though our Mainboards should have been similiar, his board is able to use 3,0 to 3,5GB of Ram - depending on the AGP Aperture Size (Funny thing is: A decrease in the Aperture Size of 128MB (from 256 to 128) leads to an Increase in available Ram of 256MB (why twice as much ? looks like Asus really screwed up here ;) With an AGP Aperture Size of 4MB i have about 3,5GB of Ram, and i'm able to use 3GB without reducing the Aperture Size. This, and nothing more, is what i had expected of the P4C800-E Deluxe. Asus Mainboard Manual (P4C800) says: [I]"When all four memory sockets are populated with 1GB DIMMs (total 4GB), the system may detect only 3+GB (a little less than 4GB) due to ICH5R Ressource allocation."[/I] So it [B]should [/B]work... If they had ever tested such a configuration :-) The strange thing is: I have found Newsgroup Posts of people sucessfully having 3-4GB of ram in the P4C800-E. Perhaps it once worked in an old Bios (didn't work in the one they shipped the board with, and that was pretty old though?)... Anyway, i'm off to the city now. Will be buying an MSI 865PE Neo2-PFISR which should work, according to the Link above. Yours sincerely, Gerald

The MSI 865PE Neo2-PFISR Board i bought turned out to be a bit more picky than all those Asus Boards. I was unable to boot (reliably) with more than (1) of my memory Modules inserted, even with Timings set manually and raised Voltage. With more than (2) Memory Modules i wasn't even able to boot at all. I therefore went to the city (again) and bought my 3rd Mainboard now. I chose the P4P800-E Deluxe (because i thought the -E Version had an Intel LAN Chip, which it doesn't... At least it has firewire which i need so it wasn't totally wrong). This board - although only slightly different to the P4P800 Deluxe (without the -E) - does not recognize as much memory as the P4P800. Instead of beeing able to use about 3,5GB with an AGP Aperture size of 4MB (as on the P4P800) i now am able to use about 3,0GB (AGP Ap = 4MB, P4P800-E). So i lost 512MB for Firewire and some additional Raid (that i don't need and have disabled...). I hope i don't loose much performance with the AGP Aperture Size set to 4MB, and will keep this Board now (it's not a PC made for 3D Gaming, so it should be ok. By the way: It's not exactly 3GB that i can use, even with AGP Ap @ 4MB its only 3044MB IIRC, instead of the 3072MB it should be. I can live with that though. Apart from this, everything works fine now. I'm using 2x Corsair1024MB and 2xInfineon 512MB in this PC and put the remaining two Corsairs in my A7N8X Deluxe. I was, unfortunately, not able to try any nVidia Cards to see if there is a difference. There was no difference between the 9600SE and my 9800PRO. Perhaps i will be able to try it with an nVidia card before i finally deliver the PC to the customer. Anyone in Germany wanna buy some brand new, only once used Mainboards ? - I got 2 spare ones here :D:

Ok, sorry about that. Won't happen again. I meant it rather as a joke - will be selling them on eBay anyway :)

ATM [url]www.asusforums.org[/url] doesn't have a for sale section, but I don't recall seeing any rules against it. Could always suggest it there.

I wouldn't have a problem with it. I'll ask the other members of the staff there, see if anyone else objects (which I doubt). Oh yeah, yes, I'm one of the staff there :biggrin: Can't remember if HoH has ever had a for sale section, maybe waaaay back in the early days, before The Great Post Trim... :biggrin: [EDIT: Ok, slapped up a thread over at AF about the idea.]

Ok, next time i'm going to canada i'm gonna kill each and everyone of them :D: I just inserted an nVidia Graphics Card into my PC, and no matter the AGP Aperture Size, i allways get the full amount of Ram (3GB is installed currently). So it never really was the mainboards fault - if i had chosen nVidia i would never had any problems at all, would have kept the first mainboard i had bought and had saved myself about 10 hours of investigating this problem, buying and swapping mainboards, and so on and so on. All this explains why i see posts all the time of people with exactly my board, who complained about only having 3.5GB or 3.8GB when i was still stuck at 2.XGB... One last question before i go to the airport ;-) : Where can I find information regarding the "anything above 2GB is not cached" in WinXP Problem you mentioned ? I never heard of that (i only know that programs can't access more than 2GB, but nothing about cache ?!?) and have some trouble believing it, so please provide me with some link. Thanks a lot ;) Yours sincerely, Gerald <longtime nVidia Fan who has only recently been unfaithful>

I'm having a hard time finding any official site where Microsoft states that Windows XP won't utilize more than 2Gb of RAM, but it is quite true. The OS won't cache any more than that and thus it won't be available for use (and will just sit there). This has nothing to do with the virtual memory, etc, only the RAM. PLUR CK

Well, RAM is generally not "cached" by an Operating system, only by the L2 and L1 Cache (and modern CPUs with integrated L2 Cache have cacheable Areas of 4GB). So what else could it cache ? Hard Disk Acesses ? If memory above 2GB is not used for Window's integrated Harddrive Caching Mechanisms ? Well i can live with Windows using the memory Areas 256-512 for caching and 512-2536 for my Appliaction :-) However, as it turned out, it is exactly the memory above 2GB that can be used only for File Caching, as no "normal" Processes have access to it. Therefor File Caching won't suffer, but improve when using more than 2GB of Ram. Also - if Windows "cannot use" memory above 2GB due to this problem, i wonder what the Microsoft/Intel Technologies PAE36 (Page Adress Extension, enables Windows to cross the 4GB Barrier on 32bit Systems, with a performance hit though, just like in old 16-Bit DOS times) AWE (Adress Windowing Extension) 32-bit x86-based systems can provide applications with a 3 GB flat virtual address space, with the kernel and executive using only 1 GB - or in combination with PAE36 even larger virtual adress spaces. I did some further research and stumbled on the following very intersting PDF [url]http://www.i.u-tokyo.ac.jp/ss/lecture/new-documents/Lectures/02-VirtualMemory/VirtualMemory.pdf[/url] which states (on page 24) that that memory above 2GB cannot be used for processes and is used only for the operating System (and it's filecache). if a /3GB Option is used for compiling the program (available on the large Server versions of Windows but also in WinXP Pro - operating system needs to be started with /3GB in Boot.ini), the OS has only 1GB of Ram, which makes the file cache suffer. This is the only finding i had concerning "cache" problems in Windows with large amounts of ram. And even that seems to be something that can be overcome when using the AWE API (but that probably makes sense only in combination with PAE). So what is the final verdict: - [B]Processes cannot use more than 2GB Ram[/B], as anything above it is OS space - OS Space is used for file caching, so [B]if you need filecaching, 3GB or 4GB makes sense[/B]. - There is a way to use 3GB of Ram in Processes - WinXP Pro supports this, if started with the /3GB option in boot.ini and if you compiled your program with 3GB support. This will lead to less space available for the OS and therefor to less file caching. - The 2GB Process Space Limitation can be overcome when using PAE in combination with AWE. PAE however is only supported in Windows 2000 Advanced Server, Windows 2000 Datacenter Server, Windows Server 2003, Enterprise Edition, and Windows Server 2003, Datacenter Edition So for a normal "user" with Windows XP Professional and normal programs, i'd say the maximum memory size that makes sense is 3GB. Depending on how important File-Caching is to you, you might also go for 2,5GB (still enough memory for the OS if a process is using it's maximum of 2GB) or 4GB (plenty of memory for file caching).

[quote]So what is the final verdict: - Processes cannot use more than 2GB Ram, as anything above it is OS space - OS Space is used for file caching, so if you need filecaching, 3GB or 4GB makes sense. - There is a way to use 3GB of Ram in Processes - WinXP Pro supports this, if started with the /3GB option in boot.ini and if you compiled your program with 3GB support. This will lead to less space available for the OS and therefor to less file caching. - The 2GB Process Space Limitation can be overcome when using PAE in combination with AWE. PAE however is only supported in Windows 2000 Advanced Server, Windows 2000 Datacenter Server, Windows Server 2003, Enterprise Edition, and Windows Server 2003, Datacenter Edition So for a normal "user" with Windows XP Professional and normal programs, i'd say the maximum memory size that makes sense is 3GB. Depending on how important File-Caching is to you, you might also go for 2,5GB (still enough memory for the OS if a process is using it's maximum of 2GB) or 4GB (plenty of memory for file caching). [/quote] Nice research! I think saying it won't "cache" the memory is just a way to glaze it over, but you're right, programs won't have access to it, only the OS... Again, nice, but I still wouldn't suggest over 2Gb for anyone not running a server and then they should probably have a board that supports registered ECC memory. PLUR CK