There is a limit to the amount of ram that can be used while not slowing the
graphics card down. That is limited by the PCI Express bus, the Ram speed,
the latency and the amount of other things using the RAM. When more than 64
MB are used, it will take longer to address all the ram, effectively making
the sum total of ram to behave as if it were slower. Larger amounts of ram
can be used as long as all of them are not accessed in the same frame (think
windows when they are overlapping). When WIN+TAB is pressed, then much more
of the buffer needs to be accessed, slowing down Windows' framerate (if you
don't believe me, open a hundred full screened highly graphical programs and
try to do WIN+TAB). I believe the DWN program is the holder of the windows
and the memory usage can easily be seen in the performance monitor's memory
section.
Ben
Something in my memory tells me that the graphics card can only natively
address the 64 MB of RAM as if it were Graphics RAM, the rest act like the
AGP aperature size did back in the old days of AGP 1, 2, 4, and 8x.
"augustus_meyer" <> wrote in message
news:597203A8-B2BF-4AEB-A68F-...
> Hi Jonathan,
>
> so it is not just a special effect of myachine, fine.
> But: I see "Total available memory: 827 MB"
> "Dedicated Video memory: 64MB"
> "SystemVideomemory: 0"
> "Shared Memory: 763MB"
>
> And these values never change. In case, your assumption would be correct,
> that memory is allocated upon request only, then the value of shared
> memory
> should change.
>
> Is there any reliable way to determine the amount of shared RAM used ?
> When using Task manager of Vista, subtracting "In cache memory" and "Free
> memory" from my 2GB still leaves 400MB missing on my machine. So it looks
> like that these 400MB is the maximum of shared video memory.
> But that is still a lot.
>
>
> Finally, there is a legal aspect: When DELL announces a video card with
> 128MB Hypermemory, it shoul dnot use more, or not ?
> Especially, because originally I only had 1GB installed, but performance
> was
> terrible.
> Because of "stolen" RAM for graphics ?
>
>
>
> "Jonathan R. Portwood" wrote:
>
>> "augustus_meyer" <> wrote in
>> message
>> news:C48B30DD-FBB0-48B6-B376-...
>> > After buying a DELL Inspiron 6400 with Vista pre-installed, I had
>> > serious
>> > discussions with tech support. Actually, now they state, it is not a
>> > bug,
>> > but
>> > a feature, a Vista feature. Here is the problem:
>> > I have a ATI Mobility X1300 graphics card, for which DELL claimed 128MB
>> > hypermemory usage.
>> > The card itself has 64MB dedicated memory, so I expected 64MB from
>> > system
>> > RAM to be shared. I had 1GB RAM installed in my laptop originally.
>> > Strange enough, Vista (graphicscard-properties) told me, that 318MB
>> > were
>> > used as shared memory. Knowing, that Vista is memory hungry, I
>> > installed
>> > 2GB
>> > RAM in my laptop. But now there are 763MB memory shared !!! Not finding
>> > any
>> > solution, to limit the amount of system RAM to be used for Hypermemory,
>> > I
>> > got
>> > in touch with DELL tech support, which finally officicially told me, it
>> > is
>> > a
>> > Vista problem, that so much RAM is used, and the laptop "Works as
>> > designed".
>> > My argumentation was, that either the graphics driver for the card
>> > allocates
>> > wrong amount of RAM, OR somehow the system information is wrong.
>> > However, that was not accepted.
>> >
>> > Any comments ?
>>
>> Hi Augustus,
>> I've got a Dell Inspiron 9300 notebook with the ATi Mobility Radeon X300
>> graphics adaptor. This has 128Mb dedicated DDR SGRAM on the adaptor.
>> Under
>> XP Pro this was all it had to use. Now under Vista Business edition the
>> Windows Graphics properties say it has the 128 Mb dedicated plus another
>> 767
>> Mb of shared system memory, giving a total of 895Mb RAM for the Graphics
>> Adaptor. I have 2Gb of system RAM installed, as you do.
>>
>> I think the key to this is that the dialog actually says 'Total Available
>> Graphics Memory', but I believe that this amount isn't always allocated
>> to
>> the Graphics Adaptor. It's the theoretical maximum amount that can be
>> allocated if needed for graphics intensive programs, such as games etc.
>> For
>> the most part the graphics adaptor is actually using far less of this
>> memory
>> than the actual maximum. The 'extra' system RAM is dynamically allocated
>> to
>> the Graphics Adaptor's use as needed and then released back to general
>> use
>> again after it's no longer needed. Personally I would say this is an
>> excellent 'feature' of the new Vista system, not a bug or 'problem' as
>> you
>> seem to feel.
>> For instance on my system, with MS Outlook 2k7 and several other programs
>> running Vista is using 931Mb total RAM at present, out of the 2Gb, hence
>> I'm
>> pretty sure the actual amount of RAM allocated to the graphics adaptor is
>> nowhere near the theoretical maximum. It's dynamically allocated as it's
>> needed and I think the main system processes would have priority over the
>> use of system RAM in a situation where there was a crunch on the maximum
>> RAM
>> in use.
>>
>> I would also like to de-bunk the idea that Vista is a memory hog. On my
>> system, which has had XP Pro SP2 prior to Vista Business edition, I saw
>> much
>> greater memory usage under XP Pro than I'm seeing under Vista. With my
>> 'normal' daily use programs open, under XP I was constantly seeing 75% to
>> 85%+ RAM usage, out of the total of 2Gb installed. Now with Vista
>> Business,
>> running the same programs, my RAM usage is hovering around 45% to 55%, a
>> significant reduction in my opinion.
>>
>> As for your system, I'd not be worried about the impact of the dynamic
>> allocation of system RAM to the Graphics Adaptor. Unless you are planning
>> to
>> run graphics intensive applications I doubt that you will ever see too
>> much
>> impact from this feature of Vista.
>>
>> HTH,
>> Jonathan.
>>