32-bit Vista Memory allocation for vidcards

[cadaveca]

Just for you, Craptacular one, i took a screenie, then removed one card, and took another.

Now, more to the point, I totally agree with you, however, because BIOSES do not deal with this function properly, allocation is not correct.

Now, does this hamper performance? I dunno.


TWO CARDS:
http://www.xtremesystems.org/forums/attachment.php?attachmentid=63698&stc=1&d=1188429917


ONE CARD:
http://www.xtremesystems.org/forums/attachment.php?attachmentid=63697&stc=1&d=1188429773

So, everyone, thoughts, comments, and explanations?

[CraptacularOne]

That is what I was talking about. When you had both cards installed it allocated the first 1GB of memory addresses to your video cards leaving windows with 3GB of address space for your RAM. In the second one where you have only one card and only 3.24GB of RAM showing it is probably because it didn't properly remap your available memory address correctly. Does your board have an option in the bios to force memory remapping?

[cadaveca]

Yes, of course. either way tho, no difference.

Also, phys-X does not affect available memory, as it should, assuming that the bios works correctly and assigns 256mb/whatever for the Phys-X mem.

Now, if i pop the cards into P5WDH, one card gives me 3.25gb, two gives 3070, add phys-X gives me 2.75gb, and tehn remap gives me a mere 2GB.

Two similar platforms, all with the same devices installed, different memory allocations.


Now, i know how it should work, but it doesn't, unless bios allows it to. Windows DOES have it's own method, but that is bypassed if bios doesn't cooperate.

Anyway, i can install 256mb x1800XL and get teh same 3.25gb available, so I do not think that vidmem AMT really affects what's available in windows, unless you get the right board, and hence my comments.

I wasn't inplying really that you were wrong, merely that boards dictate it, not windows, and thereby the listing theo posted cannot be taken for anything other how the bios is set up.

[CraptacularOne]

Yes, of course. either way tho, no difference.

Also, phys-X does not affect available memory, as it should, assuming that the bios works correctly and assigns 256mb/whatever for the Phys-X mem.

Now, if i pop the cards into P5WDH, one card gives me 3.25gb, two gives 3070, add phys-X gives me 2.75gb, and tehn remap gives me a mere 2GB.

Two similar platforms, all with the same devices installed, different memory allocations.


Now, i know how it should work, but it doesn't, unless bios allows it to. Windows DOES have it's own method, but that is bypassed if bios doesn't cooperate.

Anyway, i can install 256mb x1800XL and get teh same 3.25gb available, so I do not think that vidmem AMT really affects what's available in windows, unless you get the right board, and hence my comments.

I wasn't inplying really that you were wrong, merely that boards dictate it, not windows, and thereby the listing theo posted cannot be taken for anything other how the bios is set up.

This is interesting and I thank you for your time in posting it. Are these done with that Vista 32bit memory allocation update that you posted?

[cadaveca]

yep. same either way.

[CraptacularOne]

What motherboard are you using?

[cadaveca]

IN those shots, P5K Vanilla. XBX1 and 2 behave similarily, as does RD600. P5WDH behaves as I mentioned above.

[CraptacularOne]

IN those shots, P5K Vanilla. XBX1 and 2 behave similarily, as does RD600. P5WDH behaves as I mentioned above.

Hmm, so you get the same memory mapping on those boards and only the P5WDH behaves differently. My original thought that was maybe with the P35 chipset being limited to 4x PCI-E in the second slot and the board sending the rest of the data over the ICH9 bridge, that maybe it was only allocating 256MB to the second card. But that may not be the case since you get similar results on other boards. Hmm...interesting.

[cadaveca]

Yeah, it's not right, at all. I don't under stand how the bios is mapping the memory regions, how it differentiates between onboard and installed items, and whether ther is really ANY bios that properly supports expansion card memory mapping. the P5WDH board was the most perplexing...I cannot fathom why it would do it that way.


However, using memtest confirms that it's the bios @ fault here, as teh same available system memory is visible in memtest as in windows...a sure sign that windows really does not have control over this.

I don't really have any vendor contacts that can help explain this, and I have tried, but my interaction with IHV's is not at the level where that sort of support is really provided...I'm merely a large consumer in thier eyes, so i don't get anything more form them than John Doe does.

I eagerly await a platform that truly works properly...part of my going through so many parts is trying to find ones that work the way they claim....and guess what...I'm still buying!

[Eldonko]

Dont bother calling asus, you will have to explein for 3 hours then they will say your mem is not compatible. :p

[cadaveca]

Heh eldonko. You were just talknig to the wrong people. Over-the phone tech support is highly lacking, as this is not the sort of job that requires any sort of certification...they fill a seat in a cubicle, give 'em a few weeks "training", and shove them on the call floor.

When looking for proper support, marketing managers, "channel" salespeople, etc, might be able to help...tech agents are useless. Not alot of people realize this...

DFI is the one company that DOES seemingly have knowledgable peopel answer the phone, but that's partly because they are so small. Crucial recently downsized, and although this may seem like a bad thing to some, I see it as "cutting out the chaff" and making a far better business unit...


Problem is that if everyone had access to the people who really know what they are talking about, most of them would end up answering silly questions, etc, etc...so you've got to keep that in mind. 1-800 ain't gonna get you nothing. Thankfully we got places such as here that you can find some good answers, sometimes. You jsut gotta figure out who's who ;)

[Eldonko]

Yep, 100% true. ASUS tech support people were useless, but when I went through Mushkin to get to a higher up contact I got the issue resolved immediately. Big difference speaking with someone that actually works on a BIOS vs. someone who is trained to get you off the phone asap. :rolleyes:

[CraptacularOne]

Yeah, it's not right, at all. I don't under stand how the bios is mapping the memory regions, how it differentiates between onboard and installed items, and whether ther is really ANY bios that properly supports expansion card memory mapping. the P5WDH board was the most perplexing...I cannot fathom why it would do it that way.


However, using memtest confirms that it's the bios @ fault here, as teh same available system memory is visible in memtest as in windows...a sure sign that windows really does not have control over this.

I don't really have any vendor contacts that can help explain this, and I have tried, but my interaction with IHV's is not at the level where that sort of support is really provided...I'm merely a large consumer in thier eyes, so i don't get anything more form them than John Doe does.

I eagerly await a platform that truly works properly...part of my going through so many parts is trying to find ones that work the way they claim....and guess what...I'm still buying!

Hmm, I'm wondering if it has directly to do with the way CF is implemented at a driver level that maybe it conflicts with some boards/Windows memory allocation table. Since CF is compatible with cards of differing memory sizes maybe it only has windows allocate 256MB for the second card? If that were the case your shown values for memory would make sense.

[cadaveca]

What's going on is beyond my comprehension, however, because Crossfire/SLi are driver-level enhancements, and are not initiated until drivers are loaded, this cannot be the case, as the bios really cannot see this functionality. You would think that it would work the OTHER way, as teh peer-to peer write finction over teh pci-e bus/spi-link would be something that I would think would get it's own allocation as well, but becuase of differeing sizes of installed system ram, it's really hard for bios programmers to give a card an allocation of it's full buffer size...a 512MB card with only 512MB system ram installed would see the OS get NO memory for itself, and maybe this is why things are teh way they are.

I assume that ASIC id would be what the bios reads in order to assign the system ram, but it seems that ALL pci/pci-e devices get 256MB(for the reason i jsut mentioned). Soundcards and network take up the remaining allocation, because as I stated before, if the primary, and only vidcard is a 256MB card, it still ends up @ 3.25GB, so this is not something that is happening to just the secondary card...it's happening to all devices.

It seems as though they either ran out of space in bios to allow it to assign differeing AMTs, or they plain and simple got lazy and just arbitrarily assign ALL devices 256MB, regardless of what it is. THis makes the most sense, as the phys-X cards only have 128MB of ram, so should not need an assignment of 256MB...that's twice what it would ever need.


Anyway, this problem extends beyond my knowledge...I'm neither engineer nor programmer, but there are only so many possibile explanations for what's going on. As you can tell by the lack of comments on this issue, this is either something that most people never consider, or something they jsut simply don't understand tehmselves. It would be great to get some sor of offical answer from someone, but all I've ever recieved as a response is "I do not know", or "you'll have to talk to .....".:lol2:

[CraptacularOne]

I think you and I are the only ones who care to know or are trying to understand it :rolleyes: And as for....

a 512MB card with only 512MB system ram installed would see the OS get NO memory

This is not true because a 32 bit OS has 4GB of memory addresses, so if only 1GB of memory addresses are needed then you have a surplus 3GB, so there is plenty of memory addresses for memory and hardware.

It would be great to get some sor of offical answer from someone, but all I've ever recieved as a response is "I do not know", or "you'll have to talk to .....".
funny how everyone knows whom to talk to but never the answer themselves huh?...lol

[cadaveca]

This is not true because a 32 bit OS has 4GB of memory addresses, so if only 1GB of memory addresses are needed then you have a surplus 3GB, so there is plenty of memory addresses for memory and hardware.

Did you catch it? what happens, if there is not 4GB? those addresses are virtualized. And as such, there is not really a requirement for the full framebuffer of these videocards to be copied in system ram...so whether it's 512MB, 256, whatever, doesn't matter, really, until you start to run out of space...


If you fully read the hotfix info, you'll see that cards with lesser ram need more addressable space, and cards with more ram need less(assuming the same work is done), as video memory can be directly accessed by the cpu.


This creates a problem tho, when these adresses are of a set amt, and you run out of space...8800 owners and R600 owners like myself, that crank up the details in-game, end up running out ofspace, and the app crashes. The hotfix should allow for the virtualization to be dynamic enough to prevent the crash, as it wasn't before.



Anyway, bios writers have been writing less adressable space as they beleive that that's all that will be needed, but they have been wrong. nVidia fortunaely have realized this, and thier bioses for thier boards work right, in most instances, and this is partly why they will not allow SLi on other platforms...there's the money bit too, but that's not all...it's also about control of the platform. AMD/ATI don't have this same control, and they get shafted in the end.