Kernel dump = ram dump?

[jlreich]

In regards to this (http://www.pcguide.com/vb/showthread.php?t=34470) thread, is ram dump the same as kernel dump?

Also, if virtual memory was set really low, say 200MB, would that effect AGP aperture in any way? I don't think it would, as the aperture is controlled through the bios, but just curious. I don't want to set my vm that low, just want to know how it all works. :)

Thanks

[Jiggy]

Mite have been better asking in that thread.

[jlreich]

You might be right Jiggy. I thought about asking there, but sometimes I start asking questions in a thread I didn't start, before you know it, it gets way off topic. Mods are more than welcome to close this thread, and I will gladly ask my questions in that thread if that is preferred.

[Paleo Pete]

Suprisingly, I had to go through several pages of Google results to get anything at all about a RAM dump, and ended up with this explanation of a Core Dump (http://search390.techtarget.com/sDefinition/0,,sid10_gci211844,00.html) which boils down to a full layout of the contents of RAM in readable form.

4 pages into another search, most of the links I see are related to Linux kernel dumps rather than Windows, and nor a thing with any explanation...I suspect a kernel dump is the same as a core/ram dump, but displaying the kernel activity rather than RAM contents.

I doubt if virtual memory has anything to do with AGP aperture size, without spending another 20 minutes digging through search results, (I'm on 28,800 dial up at the moment) I'm pretty sure the AGP Aperture is related to physical RAM. In most cases it should not be set higher than 64MB unless you have a LOT of RAM...as in 512MB or more. I've never seen any noticable performance difference between 64MB and 128MB AGP Aperture settings.

At risk of posting misinformation, if I remember correctly the AGP Aperture is the amount of memory alloted for "shadowing" or similar function, only used in graphics intensive situations, so that amount of RAM is going to be dedicated to video use when the computer is really loaded up with heavy graphics. That means programs can't use that RAM, so if you set it higher you'd better have plenty to cover the rest of the system's needs, graphics will take preference in memory allocation.

If that explanation is incorrect, someone with a bit faster than my snail's pace connection can look up some info and feel free to make a correction. It's been a while since I looked it up and I can't remember the details too well, just the overall idea. More than 64MB AGP Aperture is usually not necessary. Right now this thing is connected at 28,800 and performing about like 14.4...rain does it every time...

[Paul Komski]

If I remember correctly, kernel memory is a 'locked' area of ram used by the system and which cannot be paged out into virtual memory. It is thus a special sub-set of the total physical ram such as that allocated to a graphics card. Other areas can also be specially designated - for example when creating a RAMdrive or for caching HDD read/writes from DOS by using utilities such as smartdrv.

Under WinXP you can choose between a minidump, a kernel dump or a full memory dump by Rclicking MyComputer -- Properties -- Advanced -- Startup and Recovery Settngs and then change the value in the "Write Debugging Information" DropDownList.

[jlreich]

Thanks for replying Pete and Paul.

Ok, from what I am gathering, kernel/core/ram dump, have the same function, taking a 'snapshot' of whatever is in system memory, for the purpose of debugging.

I didn't know AGP aperture existed until I finished a recent build that had the aperture options in the bios. I didn't even give it much thought until I installed Half Life 2(very graphic intensive), and was getting low performance on a

Rosewill ATI 9600 256MB 128bit
1GB pc3200
Celeron D 2.4GHz 533FSB

Noticeably lower than

ATI 9600se 128MB 64bit
1GB pc2100
Athlon XP 2400+ 266FSB on another machine. :confused:

After researching, I found that no one really seemed to know what the best setting for AGP aperture was. Some suggested 1/4 of system ram, some said 1/2, some said go for the gusto because aperture is not allocated until it is needed by the video card. Some said between 64 and 128MB, but no more than 256MB.

Aperture was set 64MB by default, so I figured what the hay, and set it to 256MB, low performance was gone. :D No choppy frame rates anymore. I didn't try 128 MB, so that may have been enough. But looking in task manager after playing HL2, peak commit charge hasn't gone above 750MB, so there shouldn't be any performance problems. Where on the Athlon machine, peak commit charge is usually around 950MB after playing HL2, without problems.

Moral of the story? I guess you just have to try different settings for your machine to find out what will work best. Hell, I might try an aperture of 512 just to see what happens. :p But I don't think even HL2 would ever need that much though. Not after the 256MB on the video card.

Sorry to ramble on, just thought this might be helpful to someone, since there doesn't seem to be that much information an AGP aperture.