I had W7 64bit running very well for a couple of months but after a crash only 512Mb memory is detected in W7 (BIOS 4Gb - Unganged for W7). When starting W7 in 'safe' mode 4Gb is detected.The system does not crash but constantly has to access my HDDs (so it creeps along).What can I do to resolve this? (rewrite bootloader or something else.....?)(Currently using XP as other part of dual boot [running fine - Ganged mode for XP 32bit])

I had W7 64bit running very well for a couple of months but after a crash only 512Mb memory is detected in W7 (BIOS 4Gb - Unganged for W7). When starting W7 in 'safe' mode 4Gb is detected.The system does not crash but constantly has to access my HDDs (so it creeps along).What can I do to resolve this? (rewrite bootloader or something else.....?)(Currently using XP as other part of dual boot [running fine - Ganged mode for XP 32bit])

Exactly why do you have your RAM running in unganged mode for Windows 7? From my research, unganged mode is simply a forced single channel mode for RAM, while ganged mode is a forced dual channel mode. Have you tried running Win 7 in ganged mode? If so, does it still only detect 512 MB?

Yep and unganged is supposedly (according to the BIOS) 2*64bit mode w/ 2*2Gb that would make sense. But why would you focus on this while my post clearly stated that the 64 bit system WAS runninggreat with UnGanged. (clock to all DIMMs)Not sure with the ganged thing 1*128bit for XP 32bit.Superspeedy!Found this: Ganged is the normal mode where RAM is used bythe twocores equally. Unganged allows each core to control it's RAM independently. I could never see much difference between the modes, so I settled on Ganged. Unganged may work better for multitasking while Ganged is better for encoding or a program that usestwo cores for the same purpose.

I'm just trying to troubleshoot. You say that you're getting all you can out of the 4 GB with XP. It struck me that it might shed some light on the problem. Seems like an obvious thing to try...I'm not entirely sure how it is with Phenom chips, but with my older Athlon 64 3400+, having the RAM in dual channel mode ("ganged" mode) most DEFINITLY made things run faster. Of course, this IS 3+ year old technology and a single core chip. It may not be quite as obvious with a faster overall system.

I am embarassed to say I haven't a clue what your BIOS docs mean by "ganged". (I hate when BIOS gives cryptic unexplained options).I suspect they mean "interleaved". That I do have knowledge of. It effectively shuffles two banks of memory together like a deck of cards. It gives faster performance by keeping each bank active in an overlapped fashion. It also benefits from this by effectively doubling the page size. A memory "page" is an increment that can be kept active with only half the mux'd RAS address, thenrepeatedly strobed with CAS.(Or maybe I have that backwards, it's been a long time). When banks are not interleaved, then they are just stacked and the benefits explained are lost. Lower performance.If you have a clear picture (pun)in your mind, please share. Thanks. egads - Google is your friend.... Here's a discussion I found on this subject.Ganged mode is a forced dual channel mode while Unganged mode is a forced single channel mode. With ganged mode, all sticks function in a standard dual channel, 128 bit mode. In unganged mode, each CPU core has it's own portion of the available memory in 64 bit mode. If you, for instance, have 2 x 2 GB sticks and a dual core CPU, each core gets it's own 2 GB stick of RAM. It's primarily an AMD thing. I haven't seen any Intel based systems that make use of this feature.

I am embarassed to say I haven't a clue what your BIOS docs mean by "ganged". (I hate when BIOS gives cryptic unexplained options).I suspect they mean "interleaved". That I do have knowledge of. It effectively shuffles two banks of memory together like a deck of cards. It gives faster performance by keeping each bank active in an overlapped fashion. It also benefits from this by effectively doubling the page size. A memory "page" is an increment that can be kept active with only half the mux'd RAS address, thenrepeatedly strobed with CAS.(Or maybe I have that backwards, it's been a long time). When banks are not interleaved, then they are just stacked and the benefits explained are lost. Lower performance.If you have a clear picture (pun)in your mind, please share. Thanks. egads - Google is your friend.... Here's a discussion I found on this subject.Ganged mode is a forced dual channel mode while Unganged mode is a forced single channel mode. With ganged mode, all sticks function in a standard dual channel, 128 bit mode. In unganged mode, each CPU core has it's own portion of the available memory in 64 bit mode. If you, for instance, have 2 x 2 GB sticks and a dual core CPU, each core gets it's own 2 GB stick of RAM. It's primarily an AMD thing. I haven't seen any Intel based systems that make use of this feature. So now we got to this point!For the XP comment :"all you can out of the 4 GB with XP" obviously I cannot access 4Gb w/ XP 32bit because 3Gb is max for XP 32bit.Can we get back to the problem @ hand, being that W7 64bit ran perfectly for months. After arestart (installed Nero 7 before it happened) only 512Mb is recognised (Safe mode start recognises 4Gb).What I will do once I am back @ home is do a clean boot. Turn off (disable) all services & startup options & restart normally. Then point by point activate the services and then startup options until the PC acts like it does now (culprit). Uninstall (or change setting[s]) for the program/service causing my problem.Everyone keeps on talking about the problem like I had never had W7 running. It was running without a hitch since 30/12/'08 until 18/03/'09.Everything installed HW/SW (even BOINC)(except logitech webcam but that's a known problem for W7) @ least 64bit

System:650WM2N-VM DVI (vga & dvi disabled)AMD +4200 64X22*2Gb 667ASUS 9600GT HTDI 1024Mb (2*DVI or 1*DVI+HDMI or either + VGA) USED5x HDD (2.01Tb)Running Unganged / clock to all DIMMsThe index W7 came up with were 5.4 (CPU)5.8 HDDGPU 7.9/6.9

I had W7 64bit running very well for a couple of months but after a crash only 512Mb memory is detected in W7 (BIOS 4Gb - Unganged for W7). When starting W7 in 'safe' mode 4Gb is detected.The system does not crash but constantly has to access my HDDs (so it creeps along).What can I do to resolve this? (rewrite bootloader or something else.....?)(Currently using XP as other part of dual boot [running fine - Ganged mode for XP 32bit]) If Windows 7 64bit was working properly and seeing all available memory for the last few months and then experiences a crash which results in it only seeing 512MB of available RAM, it sounds as if you have a serious hardware issue at hand. The constant HDD access is probably due to the OS having to make use of swap since it only now sees and recognizes 512MB. I have similar occurrences with RHEL in the past. Personally, I would start to investigate memory issues with a good memory tester such as the visually communicative and thorough Memtest86 or the built-in, convenient Windows 7 Memory Diagnostics (use the former if available). With a case such as this, I would probably test the memory using both tools and then start to investigate other possible hardware issues such as loose or unseated memory chips or video and/or expansion cards. I have to admit that I am unfamiliar with the ganged and unganged thing as I primarily tend to use Intel chips and Intel based motherboard and chipsets (when I have the option to choose). Regardless of ganged or unganged mode, if all was well earlier and no other hardware or BIOS changes were made, it seems like the crash points to a possible hardware fault or failure.

I'm notassuming that you never had it running before. I DO, however realize that something changed. It was seeing all 4 GB before and now, it'sbarelyseeing ONEEIGHTof the two sticks of RAM you've got installed. My thought was that the driver(s) for the memory weren't seeing the RAM in the mode you have them in, they MIGHT possibly work in the other - it's worth maybe 10 -15 minutes worth of experimentation to see if the ganged mode might work out better with your current configuration. If nothing else, and if it does work, your computer won't be running like molassass uphill in January and you can do further troubleshooting without having to resort to Safe Mode.So you say you installed Nero before it went south. Now then, was that just before it started ignoring your RAM or did that happen some time after the fact? Have you considered uninstalling Nero to see if that may have had an effect? Nero 7 is two generations out of date. The latest is Nero 9. There may be something in Nero 7 that's causing the problem. You mentioned a crash when this started? Any information as to what crashed exactly? You also mentioned that Windows 7 will see all 4 GB when you're in Safe Mode. Ok... It sounds like something is being loaded - a driver or an app - that isn't being loaded in Safe Mode and is causing this issue. Have you considered a System Restore back to a Restore point just prior to this starting?

I'm notassuming that you never had it running before. I DO, however realize that something changed. It was seeing all 4 GB before and now, it'sbarelyseeing ONEEIGHTof the two sticks of RAM you've got installed. My thought was that the driver(s) for the memory weren't seeing the RAM in the mode you have them in, they MIGHT possibly work in the other - it's worth maybe 10 -15 minutes worth of experimentation to see if the ganged mode might work out better with your current configuration. If nothing else, and if it does work, your computer won't be running like molassass uphill in January and you can do further troubleshooting without having to resort to Safe Mode.So you say you installed Nero before it went south. Now then, was that just before it started ignoring your RAM or did that happen some time after the fact? Have you considered uninstalling Nero to see if that may have had an effect? Nero 7 is two generations out of date. The latest is Nero 9. There may be something in Nero 7 that's causing the problem. You mentioned a crash when this started? Any information as to what crashed exactly? You also mentioned that Windows 7 will see all 4 GB when you're in Safe Mode. Ok... It sounds like something is being loaded - a driver or an app - that isn't being loaded in Safe Mode and is causing this issue. Have you considered a System Restore back to a Restore point just prior to this starting? DarienHawk67: My XP32 bit still recognises 3Gb (out of 4) so it's not a h/w issue, but thanksNow for Wolfie. I ran my W7 64bit system unganged (clock to all DIMMs) & it was performing beautifully (ganged hung/froze quite a bit). Just a b!tch when I have to switch to XP 32bit (change to ganged). It started after rebooting the 2nd time after install.Me and my dumb self did access the same files in both systems (dual boot system) which corrupted my torrent directory. [M]Utorrent has become unusable. Still in the process of moving everything off of the HDD with the corruption for a clean format. (it is 500Gb but have plenty of HDD space left to temporarily place the 350Gb onto it) They are all 7200rpm Western Digital HDDs.My PC never really shuts down except after installations etc. As a matter of fact it is on as we speak.[not important but interesting - with 512Mb W7 never crashes but it constantly reads the HDD - CPU is hardly being used - takes a good hour to load but when you dare toclick anything after it is busy for another 30min (not CPU busy)]

. . . DarienHawk67: My XP32 bit still recognises 3Gb (out of 4) so it's not a h/w issue, but thanks. . . [not important but interesting - with 512Mb W7 never crashes but it constantly reads the HDD - CPU is hardly being used - takes a good hour to load but when you dare toclick anything after it is busy for another 30min (not CPU busy)] Although that may seem like the case that hardware is good because another OS works properlyWindows XP in this casebut it may not be necessarily so. Some operating systems are more stringent to hardware tolerances than others. Also, Windows 7 manages memory differently than XP; therefore, it is a very good possibility that it may see and discover issues that XP will not. It has already been shown that Windows 7 is not as tolerant as Windows XP was when it comes to hardware that may be on the fringes. Nonetheless, it is still a good idea to do a thorough test of your memory with a dedicated memory tester just so that you can unequivocally eliminate that factor. In another thread somewhere, there was another poster who swore up and down that his hardware was good, only to find later that he actually had a questionable motherboard. Once he replaced it, Windows 7 flew like a F-22 in supercruise mode. Again, the constant HDD activity is probably due to it using swap (virtual memory in Windows terms) due to its diminished memory footprint. With 1GB being the recommended minimum, you are now running an OS that was installed and configured for a full 4GB on 50% of the official recommended minimum. Actually, it is quite surprising that Windows 7 even boots. Accessing data via virtual memory will significantly decrease performance due to increased disk I/O, but it may not necessarily result in increased CPU usage. There is nothing weird here as this would be normal, expected behavior for a system that is usingliterally12.5% of the memory on which it was installed (512MB/4096MB). Pull up Resource Monitor and take a good gander at disk I/O, providing you can even get Resource Monitor to load in a reasonable amount of time. If you want a histogram, so that you can chart and view what went on over a period of time, use Performance Monitor. Don't forget to check your event logs also. Dont make assumptions based on feelings and what seems like common sense. There is a lot that happens in the background behind the GUI that may not be as obvious as what is shown on the screen. The only way to ensure what is or is not causing an issue is by using methodical testing techniques. Otherwise, you could go down long troubleshooting paths and experience days of frustration. Good luck to you and I hope you get your issue resolved.

Already being addressed in this thread: http://social.technet.microsoft.com/Forums/en/w7itprogeneral/thread/f22c9dbf-a296-4741-8456-8e44ca5c50f1.

M Kraak Please do not post duplicate threads on the same topic. I am merging this thread with your other thread. Thanks for understanding. Ronnie Vernon MVPForum Moderator

I recommend that you turn the computer off.Remove all RAM.Boot it up (with no RAM) and listen to the annoying beep codes.Shut it off.Install one stick of RAM (not the one originally in that slot).Turn it on and go into BIOS, save settings.Boot it up to Win7.Shut it back down.Install the remaining stick.Turn it on and go into BIOS, save settings.Boot it up to Win7.Ive done the above on I-dont-know-how-many computers and learn a lot from the different results I get.T.R.

M Kraak Please do not post duplicate threads on the same topic. I am merging this thread with your other thread. Thanks for understanding. Ronnie Vernon MVPForum Moderator Not sure whether it belonged with performance or miscellanious.We can close the topic now as I am set to proceed with resolvingbut firstI need to re-format a 500Gb HDD because it is giving me and my PC a headache (used to be an external HDD). Copied 350Gb to other drives last night. (still 60Gb to go) After that I will run chkdisk I: /r (yep I) to rescue about 150Mb of corrupt files. (copy these to another location aswel) Then a complete re-format (not quick) of I:\.Start W7 in safe mode & deactivate services & startup programs (I know safe mode detects 4Gb). Then re-start & see whether the situation still exists. If so I will rewrite the bootloader through BCDEDIT (write poss. changes).I am not going to chase ghosts, I know my RAM is fine and know how the corruption of the I: drive happened (I now know how to avoid this) & am pretty sure I will be able to post the word 'RESOLVED' tomorrow.Thanks everyone!

. . . DarienHawk67: My XP32 bit still recognises 3Gb (out of 4) so it's not a h/w issue, but thanks. . . [not important but interesting - with 512Mb W7 never crashes but it constantly reads the HDD - CPU is hardly being used - takes a good hour to load but when you dare toclick anything after it is busy for another 30min (not CPU busy)] Although that may seem like the case that hardware is good because another OS works properlyWindows XP in this casebut it may not be necessarily so. Some operating systems are more stringent to hardware tolerances than others. Also, Windows 7 manages memory differently than XP; therefore, it is a very good possibility that it may see and discover issues that XP will not. It has already been shown that Windows 7 is not as tolerant as Windows XP was when it comes to hardware that may be on the fringes. Nonetheless, it is still a good idea to do a thorough test of your memory with a dedicated memory tester just so that you can unequivocally eliminate that factor. In another thread somewhere, there was another poster who swore up and down that his hardware was good, only to find later that he actually had a questionable motherboard. Once he replaced it, Windows 7 flew like a F-22 in supercruise mode. Again, the constant HDD activity is probably due to it using swap (virtual memory in Windows terms) due to its diminished memory footprint. With 1GB being the recommended minimum, you are now running an OS that was installed and configured for a full 4GB on 50% of the official recommended minimum. Actually, it is quite surprising that Windows 7 even boots. Accessing data via virtual memory will significantly decrease performance due to increased disk I/O, but it may not necessarily result in increased CPU usage. There is nothing weird here as this would be normal, expected behavior for a system that is usingliterally12.5% of the memory on which it was installed (512MB/4096MB). Pull up Resource Monitor and take a good gander at disk I/O, providing you can even get Resource Monitor to load in a reasonable amount of time. If you want a histogram, so that you can chart and view what went on over a period of time, use Performance Monitor. Don't forget to check your event logs also. Dont make assumptions based on feelings and what seems like common sense. There is a lot that happens in the background behind the GUI that may not be as obvious as what is shown on the screen. The only way to ensure what is or is not causing an issue is by using methodical testing techniques. Otherwise, you could go down long troubleshooting paths and experience days of frustration. Good luck to you and I hope you get your issue resolved. Thanks but you keep overlooking the FACT that W7 64bit was running like an F22 already. So I have to backtrack & check everything that happened between then and now! Before I can take ANY action I have to make sure that all components (this case I:\ HDD) function properly. Several files on I:\report 'cyclic redundancy errors' that need to be either fixed or deleted. I am almost at the point where I can proceed with the rest of the issues. (want to avoid chkdisk on a75% full HDD, but rather focus on the subset of files that indicate this problem) Last night I almost finished copying, tonight I will do the fixing and will let you all know what to do to fix (I guess mine only) the problem.

. . . .. . . . Thanks but you keep overlooking the FACT that W7 64bit was running like an F22 already. So I have to backtrack & check everything that happened between then and now! Before I can take ANY action I have to make sure that all components (this case I:\ HDD) function properly. Several files on I:\report 'cyclic redundancy errors' that need to be either fixed or deleted. I am almost at the point where I can proceed with the rest of the issues. (want to avoid chkdisk on a75% full HDD, but rather focus on the subset of files that indicate this problem) Last night I almost finished copying, tonight I will do the fixing and will let you all know what to do to fix (I guess mine only) the problem. The FACT is that hardware fails. One day everything can be great, the next, not. If that were not the case, you would not be having the issue you presently have. If you want to make sure all of your hardware components are good, a very good place to start that is very easy and will cause no damage at all is to test your memory. This is not chasing ghosts, but confirmation of its status; booting to another OS is not confirmation. From there, you then proceed to other components in a methodical manner. You want to fix your files that produce CRC errors, but you dont want to take the time or investment to do a complete chkdsk. Okay. I wish you well. Keep at it and let the forum know what you finally ended up doing to resolve your problem.

. . . .. . . . Thanks but you keep overlooking the FACT that W7 64bit was running like an F22 already. So I have to backtrack & check everything that happened between then and now! Before I can take ANY action I have to make sure that all components (this case I:\ HDD) function properly. Several files on I:\report 'cyclic redundancy errors' that need to be either fixed or deleted. I am almost at the point where I can proceed with the rest of the issues. (want to avoid chkdisk on a75% full HDD, but rather focus on the subset of files that indicate this problem) Last night I almost finished copying, tonight I will do the fixing and will let you all know what to do to fix (I guess mine only) the problem. The FACT is that hardware fails. One day everything can be great, the next, not. If that were not the case, you would not be having the issue you presently have. If you want to make sure all of your hardware components are good, a very good place to start that is very easy and will cause no damage at all is to test your memory. This is not chasing ghosts, but confirmation of its status; booting to another OS is not confirmation. From there, you then proceed to other components in a methodical manner. You want to fix your files that produce CRC errors, but you dont want to take the time or investment to do a complete chkdsk. Okay. I wish you well. Keep at it and let the forum know what you finally ended up doing to resolve your problem. DarienHawk67: It is certainly not the case that I did not want to run chkdsk. I said I wanted to do this on the drive once all 'good' files are copied to another location &removed from the suspect HDD. "(want to avoid chkdisk on a75% full HDD, but rather focus on the subset of files that indicate this problem)"DarienHawk67: If there was any reason whatsoever to suspect the memory I would have taken your suggestions to heartI lost 2 files to cyclic redundancy check problems. Total 525Mb (out of 350Gb) lost. Bought a new HDD because the 1st file placed on the HDD with CRC error showed CRC error immediately. 500Gb out 640Gb in. Then started W7 in safe mode,disabled services and startup programs & restarted. W7 came up immediately w/o problems (4Gb memory). So far I have turned 75% of the processes & startup programs back on also w/o problems. I am now zooming in on the processes that may be causing the failed memory detection.I will update a.s.a.p. which proces is at fault.I know my PC like the back of my hand. Upgraded it from a P4 1.7 512RAM (Rimm) (300W) into a Athlon 64x2 +4200 4096RAM (DDR2) (650W) (as if.... LOL). Turned my mum's p.o.s. into a P4 1.7 512RAM (Rimm) will change her 250W PSU to 350W at some point in time (I have it laying around). It is like a car, once you know how your own car is supposed to function you should also know when something is amiss with said car.p.o.s. is not something to write out without someone being offended so think of something.

Well the issue ended as weird as it started.I disabled all services & startup programs, W7 starts normally 4096Mb detected.Then I turned on all services again & rebooted. (problem came back 256 detected but system did respond quicker)Turned all back off & activated services A-D rebooted (registry changes were detected - SpyBot)Same for E-G, H-J, I-M, N-P, Q-S, T-W (all came with registry change detections, all OK after reboot)Then started working on the startup programs of which I had about 15.Started them in 3 parts: 1-4, 5-9,10-15. (each time rebooted & W7 kept starting w/o problems - also came with the registry change messages)W7 is now back up & functioning normally.Conclusion: Something must have been wrong with the registry involving startup. Completely rewriting this part of theregistry seems to have fixed the problem.