help ram!!

[Rollz]

Salve a tutti!
Ho un problema che non riesco a risolvere. Per iniziare vi dico la configurazione

i7 950
p6x58d Premium
6gb(3x2) Corsair xms3 1600 CL7

ho da poco acquistato un ulteriore kit identico per arrivare ad un totale di 12gb e qui iniziano i problemi
Installo il secondo kit e quindi mi trovo con 6 ram da 2gb, accendo il computer, partono le ventole e dopo un secondo si rispegne e subito dopo riparte..questo succede 3 volte(penso sia il memok che tenta di fare qualcosa), la terza volta inizia a caricare windows. Clicco con il tasto detro su computer per vedere i GB di ram e mi dice che ne ho solo 8gb..bene...spengo tutto e stacco l'ultima ram, quella che si trova nello slot C2..il pc parte senza problemi e senza riavvii e mi vede 10 gb..ok..inverto tutte le ram per vedere se è un problema di ram..ma tutte sembrano funzionare..quindi ritento, metto tutte e 6 le ram e riprovo..tutto come prima sempre 8 gb, apro cpuz e mi dice che sono installati 12gb..bene..quindi?
inizio a cercare su forum inglesi ed ho scoperto che la piattaforma x58 spesso da questo problema. Ho provato a seguire i consigli che danno ma nn sono riuscito a risolvere..voi avete qualche consiglio?

questo è quello che dicono nei forum inglesi:


Across various forums, folks reporting sometimes that they detect less memory available in windows, bios, memtest86+/DOS, than physically installed. For example, installed 6GB or 12GB and only detecting 4GB or 8-10GB respectively.

I thought I'd outline some possible reasons for detecting less memory than installed:

1. incorrect CPU VTT (uncore) voltage set - what Asus terms as QPI/DRAM voltage, Gigabyte terms as QPI/VTT while most other boards refer to it as CPU VTT voltages. Vdimm is DRAM Bus Voltage in bios.
2. incorrect QPI/DRAM to VDIMM relationship - every cpu/mem pairing will have an optimal voltage differential between QPI/DRAM to VDIMM voltage usually between 0.01 to 0.5v difference. Fall out of the optimal differential voltage for cpu/mem pairing will = less memory detected and/or lower memory bandwidth reported compared to when optimal voltage differential is in place. You also want to read Intel Core i7 920 Overclocking Introduction Guide on X58 to observe some guidelines such as keeping Uncore memory frequency at 2x times that of DRAM memory frequency - so at 2:1 uncore to memory frequency ratio. If you set your uncore higher than 2x memory frequency you will need way more QPI/DRAM (uncore) and VDIMM memory voltage to get stable (see tests).
   • Example, say you have 6x2GB @1333mhz working fine at 1.35v QPI/DRAM with 1.65v VDIMM. You try to overclock the memory to @1600mhz speeds, and you bump VDIMM from 1.65v to 1.75v and now only see 8-10GB detected. You've moved out of the optimal differential range for QPI/DRAM to VDIMM which @1333mhz was 1.65 - 1.35v = 0.3v. At 1.75v VDIMM you left QPI/DRAM at 1.35v so 0.4v differential voltage. Then you bump QPI/DRAM to 1.45v to keep 0.3v differential voltage and 12GB is detected again. Now this is just an example, it could be you need 1.85v VDIMM for your memory to be stable and if 0.3v is optimal differential voltage it means you need QPI/DRAM set at 1.55v
3. Setting some important voltage settings to AUTO instead of lowest manual available voltage option. See 2nd post here for suggestions.
4. faulty memory modules
5. faulty memory dimm slots
6. sort of combination of 4+5 above where memory modules like particular memory dimm slots - could come down to PCB differences for each module along with voltages for QPI/DRAM and VDIMM.
7. If you see full memory size in DOS/memtest but not within windows, then it could be due to 32bit/64bit memory addressing size being chewed up by video card and pci/pci-e devices as explained at [info] Windows maximum supported memory size and http://msdn.microsoft.com/en-us/libr...8VS.85%29.aspx. So if you have 6GB installed, but have 1GB video card on 32bit OS you may only see between 2.25-3GB of memory available in windows. On 64bit OS, you may only see 3.5-4.5GB memory available. If you add other PCI-E devices like sound cards, then that also further eats into available windows memory. Windows 7 users: read [info] Windows 7 usable memory less than physically installed memory
8. Update: Added another possible reason, too tight tension in mounting cpu cooler to motherboard. Improper contact of cpu pads with socket might also result in less memory detected. So especially for water cooling folks to try loosening the screws and tension a tad for cpu mount. You can try removing cpu from socket as well and reinstalling/remounting cpu cooler and see if that helps.
9. Update: Apparently short circuiting the motherboard can cause memory detection errors as well i.e. check cpu cooler's back plates and if they short any part of the backside of the motherboard. Example here and here.

 

[Rollz]

nessuno ne sa qualcosa?