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Asus P5B compatibility Issue with 2 pairs of TWIN2X2048-8500C5D


Boris187

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Hello,

 

I recently purchased two pairs of Corsair Dominator Twin2x2048-8500C5D and have run into some serious issues getting them to work. Initially I installed all 4 making sure to match up each pair properly in the slots, even though all 4 were the same version and batch, figuring that the auto settings should be enough to just get up and running I started up the pc and the fans started spinning yet I got no video. I then went into the bios and proceeded to try to find a setting that could at least get me into windows, the only way was to run the ram @ 266mhz, nothing else would allow me to even post nevermind get into windows. I then decided to try and remove a pair of the ram and was then able to use 400mhz but could not get that with all 4 dimms installed.

 

I had thought initially that I should have no problem since your memory configurator showed the ram and mobo as compatible but believe that it is a two fold issue, 1st, the mobo apparently doesn't like having all 4 slots in use even if I boost the power to the NB and 2nd, it appears that the info I got on the ram had shown this as 64bit, not 128bit which I have since found out that the ver4.1 ram that I got was 128bit which is not compatible with my motherboard nor dozens of others that I have looked into online. Keep in mind the only reason I purchased 4x1gig rams was that most of the 2gig rams were using the 128bit which I knew my mobo did not support....only to get 1gig sticks that were using it as well. Unfortunately Amazon will not let me return them so I am stuck with ram that doesn't even work @ 800mhz nvm 1066mhz.

 

I know that the individual rams do work since I tested each one seperately with memtest and they all passed with zero errors @ 800mhz but could not get them to work at all @ 1066mhz. I'm not really sure what I should/could do at this point, I have spent the last 3+ days searching forums online, playing with bios settings and running memory tests.

 

Any advice or help would be greatly appreciated since I don't really know where to go from here.

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Please enter Here and document your system hardware being as specific as possible. If you post there, then we don't have to continually look back to see your hardware.

 

Please research this thread and we can then go on to see what we can do with helping you find stability. It is an entirely different event to run a kit verses two kits.

 

http://www.houseofhelp.com/v3/showthread.php?t=64360&highlight=Unpredictable+results+QUAD2X4096+Gigabyte+X38-DS5

 

Once you have studied this thread, please post back here and we can move onward.

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Ok, I have updated my pc info under my profile and read over that thread you linked, however I have read that one several times over even before I posted here as well as hundreds of others between these forums and several others and tried many of the things suggested in them, one problem I have though is that with the P5B I am very limited to what I can do, my memory multiplier is locked, voltage settings make huge jumps so small increment increases are impossible. I am thinking of replacing the mobo since it is the oldest piece aside from the case and is creating the biggest bottleneck due to the limited adjustments. What I am currently looking at is the Asus Rampage Formula which looks to even support the 128bit dimms that I have even running 4x1gig but won't be able to purchase that for at least another month and would like to at least get the system running stable between now and then.

 

Now I do realize that by overclocking the CPU I should be able to get the ram running clocked higher, but I am afraid to do it with the stock fan/heatsink and do not want to fry a CPU I only got 2 weeks ago.

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  • Corsair Employees

With 4 modules I would suggest setting the memory frequency at DDR667 and set the memory Voltage to 2.1 Volts and set the NB/MCH/SPP Voltage to +.05 Volts as well and test the system with http://www.memtest.org. In addition, with some MB's (Mostly ASUS) you have to disable legacy USB in the bios when running any memory test.

 

And with that MB running 2 modules on that MB DDR800 would be suggested as it will not officially support DDR1066 memory.

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There lies the problem I have, having read several other posts here before I posted about my problem I did try setting to DDR667, increased to 2.1v on the memory, but in order to increase the voltage on the NB it goes from 1.25 to 1.4 then to 1.55....In trying them, all I got was once I changed the settings and saved, the system rebooted, started for about 2 seconds, shut down, restarted and just sat there with no video and I had to pull the plug on the power supply just to get a message saying overclock failed, press F1 for setup or F2 to revert back to default. Now what I don't know is if it's a problem of when I try the NB voltage at 1.4 am giving it too much extra juice? I have no option of giving it less and no matter what I have tried I either get what I just described or I get a no post and have to either switch back to default settings or enter setup to try something else.
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It seems what I thought was wrong regarding that new mobo I was looking at, after reading the user manual .pdf I downloaded from Asus, it shows this mobo as not supporting 128bit chips as well and have yet to find a single one that does which leads me to believe that I am going to have problems with these ver4.1's no matter what I do. It does show in the QVL that it supports CM2X1024-8500C5 in single, dual and quad, but I cannot find those listed on your website to find out if those are 64/128bit :[pouts:
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In responce to what Ram Guy said as far as "And with that MB running 2 modules on that MB DDR800 would be suggested as it will not officially support DDR1066 memory." I would like you to note that in one of your links in your sig to what timings my dominator ram would use it shows specifically a P5B as one of the 2 rigs the settings were tested on.....I do realize that this may not be the case as far as running 4 dimms without having to OC the CPU/NB but as far as running 2 modules I would think that it should, but again I believe this was probably tested using the 64bit dimm's NOT the 128bit's that my versions are. Which leads me to wonder why on earth Corsair would have switched to 128bit dimm's since they look to not be supported at all on most new/old mobo's.
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Ok, I got to thinking while looking at the suggested memory timings listed in that link in your sig and I am wondering about a couple of things, first off, it is setting to DDR800, yet the timings are for the DDR1066, ie: SDRAM Active to Precharge Delay (tRAS): 15T, and the DDR2 Voltage control: 2.20V Ver 1.x (2.1 Volts for 2.X), would I be wrong in thinking that the SPD lists at 18T and 1.8v @ DDR800? Also it shows setting the CPU External Frequency: Manually set to 268 MHz, mine by default is 266 Mhz but I also have a locked Multi @ 9x, is the very mild OC to get over a strap? I'm just grasping at straws but the more I research on the subject....so far well over 40 hours in the past 1.5 weeks regarding memory timings, straps etc the more I wonder if I should try to do a mild OC to the CPU if there is possibly a strap that is holding me back from getting the 4 dimm's at least up to DDR800.
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  • Corsair Employees
With 4 modules I would suggest setting the memory frequency at DDR667 and then you will have some head room to over clock but with the memory at DDR00 if it will run at DDR800 4 up you might get to DDR840-DDR930 tops from what I have seen of that MB.
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Ok, I just had some luck, I did a mild OC to the CPU, had a bit of trouble when setting anything but the voltage on the ram, but set it to 2.1v, CPU is at 9x300, ram is at 449.8Mhz @ 2:3 5, 5, 5, 15, 2T with all 4 gigs, temps went up a little from what they were before, but only about 4 deg C. on each core from stock, I have yet to test anything but seems ok so far, here is a screenshot with Hardware Monitor and CPU-Z running. Going to test a bit but wanted to post about what I managed to do. :biggrin:

 

http://img242.imageshack.us/img242/5647/9x300ocnk3.th.jpg

 

Just noticed that it's shown at the 6x Multi in the SS, even with speedstep turned off, not sure what the deal is with that....but whatever, it's running and not just at DDR533 anymore.

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Well, that's not going to work, Core temps went through the roof just benching the memory (60-69 deg C) and they did poorly at that, guess it's back to the bios to try something different, but an OC is apparently out of the question with this stock fan/HS:sigh!:
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Ok, I have tried a few different OC's one of which stands out quite a bit as far as the benchmark results, I am just unsure about the core temps, running 9x335 for a 3.01ghz, DDR1004 2:3 @ 5, 5, 5, 15, 2T(shows 1T in SiSoftSandra) after running the SiSoftSandra memory benchmarks it scored 6.37g/s in the memory bandwidth test, 75ns in the memory latency test and 43.2g/s in the cache & memory test. Core temps at idle range from 43-49 deg C and at full load during the series of tests maxed out between 66-72 deg C. Going to try a few other tests to see how stable it is but it seems fine so far.
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Ok, at the 9x335mhz I ran Prime95 Blend for about 30 minutes w/o any errors or warnings and only stopped it due to the high temps the cores were getting up to, mid to upper 70's C, so I will need a better fan/hs for the CPU but otherwise it is running great. I then played Crysis single player for about 1.5 hours @ 1680x1050, very high textures and 4xaa in DX10 and it ran flawlessly during which the highest temp the cores hit were 63 deg C, no where near the highs they hit during Prime95 and since that is more than likely the most intensive application I currently have on my system I would have to say that I am very happy with the system overall.

 

I will look into better cooling and will still probably pick up a better mobo just so that I can tweak the settings better since this P5B is just so limited, I can't even manually adjust the voltage to the cores since the lowest option I have is 1.7v which is way above the 1.39v that Hardware Monitor is currently showing which is probably a bit high and bringing the temps up higher than they could be at.

 

I was also wondering if anyone knows of a good application that I could use to try and tighten up the lower timings on the ram, CPU-Z shows very little and SiSoft Sandra doesn't give much more than that so I pretty much had to wing some of the numbers beyond the 5, 5, 5, 15 since there are no options to set them individually to auto unless I let the mobo set all of them and it gives me a much lower DDR speed than when I set them myself.

 

I want to thank everyone for the help and advice, by all means if you think of anything else that might benefit what I have done so far it would be very much appreciated. :biggrin:

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Well I ordered a Noctua NH-U12P CPU Cooler and will play around a bit more once that comes in since the temps aren't exactly to my liking right now, but one thing I noticed today after installing a couple of updates was that when I restart the pc, rather than just doing a normal restart, it actually powers down for about 2 seconds and then reboots, is that normal for an OC? It only seems to do that when the CPU is OC'd, at normal 9x266 it does not do that, but any OC, even 9x268 it does, or is that signs of a problem or bad setting in the bios?
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