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Computer won't boot with 4Gb RAM, fine with 3

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July 31, 2008 7:15:22 PM

Hey guys, this is my first post here but I've been lurking around for quite a while. I have a problem. I just had a new PC built for me, I had gone with 2 Gb of ram with the intention to upgrade later. Yesterday the ram came in I installed 2 more GB's and the computer would not boot. I removed one of them and I successfully made it into windows. Then I restarted again and the computer would not boot with my external HD attached. I'm honestly very confused here.

System is -

E8400@3ghz
2GB Ram@ 800 mhz (currently 3)
9800gtx (not that that matters)
Asus P5N-D moherboard
650 watt Corsair PSU
Vista 32

Can anyone explain why this is happening?

More about : computer boot 4gb ram fine

July 31, 2008 7:36:57 PM

One of the sticks might be bad. Did you try with your original 2 gb plus the other stick?
July 31, 2008 8:37:17 PM

Do you mean my oldm sticks plus the one that may not work? No I haven't but I have the other of the new ones in there now and its working fine.
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July 31, 2008 8:55:03 PM

Hi majorbromly

Try to set your 4 Gb RAM speed at 667 MHz instead of 800 MHz in the bios

July 31, 2008 9:00:03 PM

Brobably dot enough voltage for 4 sticks. Check memory voltage in bios it should be 2.1V not 1.8V or even 2.2 for 4 sticks.
July 31, 2008 9:16:52 PM

You most likely got a DOA stick of RAM. Send the kit back for a replacement. When I got a bad stick my PC wouldn't even give a POST code, and it sounds like you got the same thing happening.
a c 109 } Memory
July 31, 2008 9:21:02 PM

If the second pair of sticks do not exactly match the original, you may have a problem. They need to be the same. Some motherboards are very sensitive to differences.

Assuming that all the sticks are the same, use memtest86+ to test out each stick individually.

Also use memtest to verify that a known good stick works properly in every slot on the mobo.

If all the sticks are good, then you may have to increase the ram voltage a bit. Look at the ram specs to see what the maximum is.
July 31, 2008 9:53:25 PM

geofelt said:
If the second pair of sticks do not exactly match the original, you may have a problem. They need to be the same. Some motherboards are very sensitive to differences.

Assuming that all the sticks are the same, use memtest86+ to test out each stick individually.

Also use memtest to verify that a known good stick works properly in every slot on the mobo.

If all the sticks are good, then you may have to increase the ram voltage a bit. Look at the ram specs to see what the maximum is.
agree!!
July 31, 2008 10:06:54 PM

I hate to tell you, but i have a P5n-e motherbaord and had the same problems that your having--When i contacted Asus regarding the problem, they told me that i was SOL cuz i didn't buy approved memory.

I was able to get my system to boot once or twice, but i had to manually set every setting for RAM in the bios.

If you check ASUS' forums, you will find many ppl having this problem.

See:
http://vip.asus.com/forum/view.aspx?id=2008071223291662...

http://vip.asus.com/forum/view.aspx?id=2008071604153450...

http://vip.asus.com/forum/view.aspx?id=2008071408204882...


Sorry to be the bearer of bad news.


Ultimately i returned my P5N-e and picked up an EVGA 680i to replace it--havne't had a single problem.
August 1, 2008 12:22:11 AM

wrong, wrong wrong and wrong but thanks for playing You need a 64 bit Operating system to recognize more than 3 gigs
August 1, 2008 12:26:16 AM

Fogartini,
you're an idiot
August 1, 2008 12:26:45 AM

Fogartini: did you even bother reading the links in my post? Jackass.
August 1, 2008 12:33:24 AM

What does anything in your posts have to do with the fact that hes running a 32 bit OS and a 32 bit OS wont recognize 4 gigs of RAM?
August 1, 2008 12:35:54 AM

Fogartini, I was about to explicitly say to not mention that limitation. I figured the tomshardware peple are smarter than that, thanks for challenging my beliefs.

ANYWAY, All of the ram is identical, Corsair XMS2 1gb sticks. I will check on the voltage though, sounds easy enough to change.
August 1, 2008 12:37:31 AM

Oki Doki good luck
August 1, 2008 12:38:26 AM

Also hesskia, what was the ram you bought that ASUS said was not approved?
August 1, 2008 12:40:04 AM

My point is, the computer regardless of OS should BOOT with 4 gb
August 1, 2008 12:41:08 AM

You've run into a common issue (not mentioned above). Having 4 DIMMs installed at once is pushing the limits of current unbuffered DDR2 RAM technology. The control signals to the DIMMs get split among all of them, so having 4 installed means the signals to each are much weaker than with only 1 installed, causing errors. The better the motherboard design and the better the quality of the RAM, the less likely the problem, but once you have it, the only solution is to try raising the MCH (memory controller/northbridge) voltage a bit, perhaps 0.05V or 0.1V. This is NOT the DIMM/RAM voltage (which you should have already set to the spec voltage specified by the RAM manufacturer for your specific DIMM part number).
Good luck!
August 1, 2008 12:48:59 AM

Where could I see my timings? The BIOS? The memory I bought is 4-4-4-12, the ones that I originally had may be 5-5-5-18. Would that cause this?
August 1, 2008 12:55:09 AM

Not sure why timings matter here, but if you run CPU-Z, you should be able to see both current timings and the SPD settings stored in each module. If you didn't buy all 4 sticks at the same time, they are DEFINITELY NOT identical, even if they have the same model number. Memory manufacturers make minor-to-major changes in their models as often as weekly.
No, different timings would not cause this, as the MB should just default to the slowest timings.
August 1, 2008 12:59:49 AM

Alright, I'll try that program
August 1, 2008 1:32:54 AM

To majorbromly:

In your original post you mentioned that you had a new PC built. Did you install Vista with SP1? The reason I say this is that the original Vista DVD would not let you boot into Windows if you had more than 3Gb of memory. MS later released a patch for this which is now included in SP1. Personally, I install vista with 2GB and then install SP1. Once that is done I install the remaining 2Gb of memory.

http://support.microsoft.com/kb/929777

I have an Asus P5N-E SLI board and I have 4x1Gb Corsair XMS RAM, SLI certified with 4-4-4-12 timings. I haven't had any problems with them. I had bought 2 in jan 2006 and bough 2 more earlier this year. I don't think the difference in your memory timings would cause a problem. But I am not sure about this. I though a faster 4-4-4-12 memory would automatically underclock to match the slower 5-5-5-18 memory.

I would try installing Vista with just 2Gb and see if installing SP1 fixes the problem. Just make sure you're using the memory with the same timings. You should also try the other options listed in the other posts. It is just time consuming and you just need to narrow down your options on what might be causing the problem. Good Luck!!

To Fogartini:

Your post about a 32bit OS is somewhat correct, however that is not the case here. Regardless of how much memory a 32bit OS will recognize, it will still allow you to boot into windows. It just won't use more than it can recognize. Also, 3Gb is not the maximum a 32bit OS can recognize. The memory allocation for RAM is done last and depends on how much other hardware have used up. A large majority is used up by the GPU. For Ex. if you use a GPU with 64MB Ram then your computer will most likely be able to recognize more than 3Gb (Which you said only a 64bit OS can recognize). If the OP decides to run two Nvidia GT 280 cards in SLI, he would be using about 2Gb for his video cards, then the OS would only be able to recognize less than 2GB.

August 1, 2008 1:42:02 AM

I installed SP1 when I set the computer up. I think that goes a long with what you said.
a c 109 } Memory
August 1, 2008 2:49:26 AM

Mondoman said:
You've run into a common issue (not mentioned above). Having 4 DIMMs installed at once is pushing the limits of current unbuffered DDR2 RAM technology. The control signals to the DIMMs get split among all of them, so having 4 installed means the signals to each are much weaker than with only 1 installed, causing errors. The better the motherboard design and the better the quality of the RAM, the less likely the problem, but once you have it, the only solution is to try raising the MCH (memory controller/northbridge) voltage a bit, perhaps 0.05V or 0.1V. This is NOT the DIMM/RAM voltage (which you should have already set to the spec voltage specified by the RAM manufacturer for your specific DIMM part number).
Good luck!

Good job Mondoman. The best explanation I have seen of the 4 stick issue.

Corsair 5-5-5-18 memory is spec'ed at 1.9v. The 4-4-4-12 memory needs 2.1v to run at that speed. I think all the memory you install gets the same voltage; you can't mix. Obviously it partly works because you can get 3 sticks running. Corsair recommends a 4gb kit to be certain that all the memory is exactly the same. They have good customer support. Open up an incident with them, maybe they can help you out.

To separate out the OS issue, test with memtest until you get all 4 sticks running. It will be faster than booting windows anyway.

---good luck---
August 1, 2008 3:29:32 AM

How long should memtest run?
August 1, 2008 3:56:10 AM

majorbromly: I have 4x1GB OCZ Platnium DDR2 800. I contacted Asus about my problem and they said they only support a 4x1gb configuration with approved memory. They went on to tell me that I might get them to work if I manually set all the settings in the bios, then up the voltages slightly if that didnt' work (see mondoman). I could never get mine to go past posting with 4 sticks installed, so I got a new board (the memory was very expensive at the time) and sold my old one.
August 1, 2008 4:10:45 AM

Most memory can run at several settings. You need to find a common denominator - if one is available - to run two different types at the same time - at a minimum at the same voltage. Run CPUZ and see what it reports for all the SPD settings for each type of memory and try a common voltage setting - if there is one. I would suggest trying to get them both running at lower timings if there is an option first - then you can try to tighten them later.
Also - are the memory chips single or double sided? This ties in to what Mondman was saying and, in some cases, having two many chip modules on double sided memory can be a problem - perhaps one without a solution.
August 1, 2008 4:44:39 AM

Double sided? What's that? sorry for ignorance ;) 
August 1, 2008 5:05:13 AM

Did you try the second pair of sticks alone in the motherboard to make sure that both are good? I still think you may have a bad stick of RAM, especially since my issue with RAM was with an OCZ stick.
August 1, 2008 5:28:43 AM

WOW this got ugly. run memtest for 30 min for now, use the new sticks only !
sorry if i missed it but what is the types of memory you have? if memory checks ok two things might be a problem 1. two different types of mem or might need to bump mem voltage up. i do agree with San Pedro
August 1, 2008 5:37:22 AM

Not sure if somebody has mentioned this but have you tried turning on Memory Remapping (or similarly named feature) in your BIOS? Solved a problem on my old system
August 1, 2008 5:40:05 AM

Run Memtest86+ for at least a few hours, or better over night. You can also find it on the Ultimate Boot CD.

You will need to burn the ISO to CD with ISO Recorder v 2 or other ISO burning software.
August 1, 2008 5:44:50 AM

Zorg said:
Run Memtest86+ for at least a few hours, or better over night.
I do agree Zorg but for now just to make sure there is not a bad stick that way he can move on to at least get the computer to boot ????
August 1, 2008 6:13:14 AM

Same thing rockyjohn said...you have probably exceeded the number of memory banks allowed by the motherboard. I've seen this problem before and it's usually caused by using too many double sided memory modules.
August 1, 2008 6:21:11 AM

fleakiller said:
I do agree Zorg but for now just to make sure there is not a bad stick that way he can move on to at least get the computer to boot ????
Well if it was me I would boot to the first 2 sticks and then try the second 2 sticks. I suspect he is having the 4 stick problem mentioned earlier. So, as said, raise the Vmch a little, which often doesn't solve the problem.
August 1, 2008 8:19:56 PM

majorbromly said:
Double sided? What's that? sorry for ignorance ;) 


Double sided memory sticks have memory chips on both sides of the stick - usually 8 chips per side. Single sided have chips of about the same physical size - although maybe a little thicker - on only one side and flat board on the other.
a c 109 } Memory
August 1, 2008 8:31:01 PM

If Memtest can run for a full pass, then you are probably ok. Bad ram will usually fail during the first pass. When everything looks ok, you could try an hour or so, and overnight if you are a bit paranoid.

You can also run prime95. This exercises the cpu as well as the memory. Be certain to select round-off checking as an advanced tab feature. Look on the log for any errors. If this runs properly for 15 minutes, you are probably good.

If you have any doubts about the compatibility of your memory with your mobo, go to the Corsair web site. They have a configurator. Enter your mobo, and you will get a list of compatible ram parts that will run on your mobo.
August 1, 2008 9:11:43 PM

What did ya'll miss about this being a documented problem on the P5N-E?

August 1, 2008 10:19:09 PM

The 4 stick problem is a problem with a lot more mobos than just the P5N-E.
Zorg said:
Well if it was me I would boot to the first 2 sticks and then try the second 2 sticks. I suspect he is having the 4 stick problem mentioned earlier. So, as said, raise the Vmch a little, which often doesn't solve the problem.

August 2, 2008 9:51:18 PM

Where do you stand on this problem? Did you up the RAM voltage to 2.1V maybe 2.2V for 4 sticks? Did you raise the Vmch any? Watch the northbridge heat on that. Did you lower the RAM to 667? Can you POST into the BIOS with 4 sticks or no POST at all. I assume that memtst86+ shows all sticks good for at least one pass. Can you post CPU, Memory and SPD tabs (one of the old stick and one of the new stick) form CPU-Z with the three sticks installed? Do you have the latest BIOS revision?

Earlier someone was saying that it wouldn't boot because of the 32bit OS, which we all know is total BS. However, 32bit will only see ~3G of RAM anyway, which we all know. My point is that the only difference between 3G and 4G is having the 3rd Gig of visible RAM in dual channel. IMO dual channel is over rated. I did some benches earlier and the bandwidth gain was disappointing, to say the least. Couple that with the insensitivity of the Core2 to memory speed/bandwidth/latency and you really are gaining very little, if any, in real world performance with 4 sticks. Maybe you would be better served to save the 4th stick in case another one dies.

August 2, 2008 10:51:36 PM

If you add the 3rd GB as 2x512MB, then all 3GB runs in dual-channel mode. :wahoo: 

I agree that dual-channel mode doesn't matter as much these days with Core2 designs and their large caches.
August 2, 2008 11:36:42 PM

I definatly notice a loss in performance without dual channel though. Everything expept games (FPS in Crysis doubled) runs slower. I haven't done anything about the problem yet, I've been pretty busy.
August 2, 2008 11:53:56 PM

Navigating web pages and such is, to me, a bit slower. Nothing I couldn't live with.
August 2, 2008 11:56:57 PM

Navigating web pages? Now I'm really surprised.
August 3, 2008 1:18:32 AM

I can cut your sarcasm with a knife ;) 
August 3, 2008 2:36:10 AM

I'm not being sarcastic. Processing power or RAM bandwidth has very little effect on navigating web pages, within reason, because the page loading is bottlenecked by the connection/web speed. The difference between dual channel or single channel should not be noticeable at all.
August 4, 2008 1:18:48 AM

Did memtest86+ show any errors? Also, how do you know you're in single-channel mode (you should be in either "flex"/hybrid or dual-channel mode)?
August 5, 2008 3:29:16 PM

With 3 sticks my motherboard runs in single channel. Also CPU-Z showed single channel. I can't even get the computer to, I guess the term is POST, with 4 sticks in. All I get is a long beep. I just figure I'll return these and grab a 4 gb kit.
!