| Installed Memory vs RAM Usable by Windows |  |
| Articles - Featured Guides | |||||
| Written by Olin Coles | |||||
| Monday, 14 June 2010 | |||||
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Installed Memory vs RAM Usable by WindowsMost PC users are familiar with the 4GB system memory limitation of 32-bit Windows Operating Systems, which is why 64-bit computing has become the standard for computer enthusiasts. Occasionally though, a computer system will not report the correct amount of RAM installed. In this article, our 64-bit Windows 7 test system had 6.00 GB of installed memory but indicates only 4.00 GB usable RAM available. While some may dismiss this as a case of defective RAM, you might be surprised by the culprit. Benchmark Reviews troubleshoots Installed Memory vs RAM Usable by Windows. Diagnosing system memory problems is usually a strait-forward chore: test each module individually using free tools such as Microsoft Memory Diagnostic or Memtest86+. This process usually roots out the defective module, and allows you to move on with replacement. Unfortunately, not all problems are so easily solved. In some cases, the computer system will work without errors or crashing, but the amount of installed memory is more than what Windows reports as usable. This is where troubleshooting can take you to task.
Windows Installed memory (RAM): 6.00 GB (4.00 GB usable)Modern computer hardware is very durable, but factory defects and improper handling still account for the majority of failures. System memory, often referred to as RAM (Random Access Memory), is the middleman between the processor and Operating System. RAM is installed into DIMM (Dual Inline Memory Module) sockets on the motherboard, which adds another component into consideration when troubleshooting. The mainboard can occasionally be to blame for memory problems, too, making it difficult to discern between faulty RAM or motherboard. But what about the CPU? Many new processors have an integrated memory controller (IMC) built into the CPU, such as the triple-channel DDR3 controller equipped on Intel Core i7 Nehalem LGA1366 processor series. Subsequent dual-channel AMD and Intel processors have utilized this technology, further complicating the process of troubleshooting bad system memory (unless you have compatible RAM and CPU components on hand to test with). In the next section, Benchmark Reviews gives a brief overview of how to diagnose desktop memory problems, and reveals how a faulty IMC can cause Windows hardships.
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Comments
Often it helps just to reassemble the CPU.
Or some Pins in the Socket are bend, could be fixed with a needle.
Seems that it can happen that the CPU has no proper seat or is twisted a tine bit.
Or by tightening the Cooler to much.
Quite often it only happen with OC and @ stock everything works.
So please make sure, if the CPU is really the case or bad contact in some way.
I am active @ PCGH-Forum and we have/had some issues like that,
most was solved without changing anything at least.
I hope you can get some more light on to it.
Best wishes
SteinSchocK
##evga.com/forums/
Sometimes in an X58 based motherboard the CPU must be lined up absolutely perfect or you will see the problem that you troubleshot. Never rush a CPU install on this type of motherboard. Double and triple check the CPU pin alignment BEFORE you close the CPU locking mechanism
best regards
rjohnson11
EVGA Forum Moderator
#lmgtfy.com/?q=x58+triple+channel+n ot+working
Simply bump up your QPI voltage and it'll be fine.
Worst comes to worst, play with the ram divider to try a few different frequencies (slower is not always more likely to work).
(i.e. Mine works in tripple channel at 1600, but won't at lower speeds.)
This issue is super common with people running 6 dimms (you can almost count on it).
Slightly less common with 3 dimms.
The real clue is that when you post, it will say 'dual channel'.
A tool like CPU-Z (and windows) will identify all 6 slots worth of dimms.
The bios will also list all 6 if you go under the section that shows timing data.
The dimms are working, and are in communication with the mainboard.
You are not in dual channel because a dimm is offline.
A dimm is offline because you are in dual channel.
Essentially, the IMC is overloaded and can't handle 3 channels.
continued ...
You can increase the robustness of the IMC by raising its voltage, or you can decrease the load on the IMC by finding a friendlier memory divider.
Try 1.35v, as that is the top end of the normal range for an i7 (intel spec).
OCers often go over this limit by a good amount.
OCing usually needs more QPI voltage.
Filling 6 slots usually needs more QPI voltage.
And, having a 'lemon' memory controller usually needs more QPI voltage.
When I initially encountered this, I went to the MSI forums.
When I got there, I found a wall of threads on the same issue.
Looking around, it was everywhere, on every i7 mainboard forum.
Hence, why just googling will turn up hits on missing ram or channels.
-scheherazade
My condolences.
( took about 4 full install/test cycles to get my first Athlon to connect reliably to RAM,
and the erors were showing-up only in the near-final controller-tests iirc? ).
Secondly, if you test a module, pull it & re-place it, you DON'T know it's reliable now.
( see the first item )
Thirdly, Memtest86/Memtest86++ should have identified that some memory wasn't being usable, directly, thereby showing the problem.
When testing, SIMPLIFY the system, so as few variables as possible are interacting, otherwise you're just doing voodoo...
Cheers,
That said, the easiest solution is simply to run the memory at 1600MHz. I know it's frustrating not getting every last iota of performance out of the memory you paid for, but really, you'll never see a whit of difference between 1600MHz and 1866MHz except in synthetic memory bandwidth tests: not a single extra frame per second in any game or anything...