using only 2x2 gig ram sticks generally gives you better memory speeds than 4x1 gig at some later date).
I just upgraded my Dell Inspiron E1505 from 2 x 1Gb to 2 x 2Gb on Vista32 and the performance change has been measurable. I get something like 3372 available for use...You shouldn't have problems. I've got a 4 gig XP32 system that works fine bar only seeing 3.25 gigs of ram.
Not entirely true, it depends on the density of the chips in use and the chipset involved. A double-density pair of sticks will go faster than four double-density sticks, but four single-density sticks will perform faster than a pair of double-density sticks and faster than a pair of single-density sticks on pretty much every Intel-based northbridge setup. I can't speak for AMD systems though...and using only 2x2 gig ram sticks generally gives you better memory speeds than 4x1 gig at some later date)
These issues are near-entirely related to Windows 2000; PAE is force-enabled on all WinXP SP2 machines that have more than one logical processor installed. Thus, if you've got a P4 with hyperthreading or ANY of the Core 2 Duo lineup (or newer), you're already using PAE if you've got XPSP2 or later. It was a requirement of the Execute Bit Disable support...Some people have the occasional issue with PAE extension drivers (Microsoft's attempt at dealing with the 4 gig limit on 32 bit systems where driver location is concerned), but I've never seen them.
I bnought 2x2gb sticks my bios reports 2072mb
really you'd think that the computer would use some sort of interleaving across the two channels.
Not entirely true, it depends on the density of the chips in use and the chipset involved. A double-density pair of sticks will go faster than four double-density sticks, but four single-density sticks will perform faster than a pair of double-density sticks and faster than a pair of single-density sticks on pretty much every Intel-based northbridge setup. I can't speak for AMD systems though...
These issues are near-entirely related to Windows 2000; PAE is force-enabled on all WinXP SP2 machines that have more than one logical processor installed. Thus, if you've got a P4 with hyperthreading or ANY of the Core 2 Duo lineup (or newer), you're already using PAE if you've got XPSP2 or later. It was a requirement of the Execute Bit Disable support...
Still have to disagree with you...
The best link I can find at this moment is here: http://www.anandtech.com/showdoc.aspx?i=1839
Even in "auto" mode, four sticks of dual-sided DIMMs performed best, and two double-sided compared equally to four single-sided sticks. There are some other overclocking concerns linked to the timings you talk about, but not at 'auto' settings at stock clocks.
Still have to disagree with you...
The best link I can find at this moment is here: http://www.anandtech.com/showdoc.aspx?i=1839
Even in "auto" mode, four sticks of dual-sided DIMMs performed best, and two double-sided compared equally to four single-sided sticks. There are some other overclocking concerns linked to the timings you talk about, but not at 'auto' settings at stock clocks.
You can check it yourself. Put 2 dimms in and look to see what the BIOS has set the timings to. Put four dimms in, and see the BIOS has slackened the timings all by itself. You can even look in the back of most motherboard manuals, and they will tell you that populating all four dimm slots will cause timings to go down.
You can check it yourself. Put 2 dimms in and look to see what the BIOS has set the timings to. Put four dimms in, and see the BIOS has slackened the timings all by itself. You can even look in the back of most motherboard manuals, and they will tell you that populating all four dimm slots will cause timings to go down.
I've only seen this behavior happen on the AMD Platform (Socket 939) with an NForce 4 chipset in relations to the command mode timing going from 1T to 2T. My Intel P965 and P35 boards do not exhibit this behavior.
These issues are near-entirely related to Windows 2000; PAE is force-enabled on all WinXP SP2 machines that have more than one logical processor installed. Thus, if you've got a P4 with hyperthreading or ANY of the Core 2 Duo lineup (or newer), you're already using PAE if you've got XPSP2 or later. It was a requirement of the Execute Bit Disable support...
To constrain compatibility issues, Windows XP Service Pack 2 includes hardware abstraction layer (HAL) changes that mimic the 32-bit HAL DMA behavior. The altered HAL grants unlimited map registers when the system is running in PAE mode. In addition, the kernel memory manager ignores any physical address above 4 GB. Any system RAM beyond the 4 GB barrier would be made unaddressable by Windows and be unusable in the system. By limiting the address space to 4 GB, devices with 32-bit DMA bus master capability will not see a transaction with an address above the 4 GB barrier. Because these changes remove the need to double-buffer the transactions, they avoid a class of bugs in some drivers related to proper implementation of double buffering support.
As a result of these changes to the HAL and memory manager, the impact to device driver compatibility is expected to be minimal on systems running Windows XP Service Pack 2 with data execution prevention enabled.