TWIN3X4096-1600C7DHXIN and dx38bt

[pietro_mile]

hi, i have buy kit 4gb pc-12800 TWIN3X4096-1600C7DHXIN for my dx38bt.

I entered the bios, i have i see that ram are recognized as ddr3 1066mhz. I have select profile 1 (1600 xmp).

Now every time I link the current and power on it's star for 1 second, switches off for 2-3 second, and start correctly. I see in bios that merory overside 1600 (standar 1066). But when i select Automatic profile (defaut 1066) on ram menu and and if i re-running the procedure "I link the current and power on" it start correctly. Why this problem?

In cpuz i can see dram frequency 533.3 mhz (1066); on spd i see max bandwidth pc3-8500f (533 mhz) not pc3-12800... Why? and the front side bus is 1332

If setting on bios profile 1 (1600 xmp), cpuz on spd i see

ever max bandwidth pc3-8500f (533 mhz) not pc3-12800..

now i have buy pc3-12800 or pc3-8500f??

another question, if i work with front side bus 1333mhz memory bus is 1332? why? (cpuz dram frequency 666.6mhz) i have this result also on bios setting xmp profile 1 and if i setting manually 333, 1333, 9 9 9 24.

 

I hope that I explained.

thanks for any reply

[RAM GUY]

According to the information you provided the memory is running as fast as it can with the CPU and MB you have. The memory frequency cannot be more than the CPU FSB with an Intel Chipset MB.

[pietro_mile]

ok thanks for reply.. but you say why when I link the current and power on it's star for 1 second, switches off for 2-3 second, and start correctly? This happens since I installed your ram manually putting the parameters or select profile 1 on bios. This behavior is correct? you have also found in your test?

thanks for attention

[DerekT]

Yes, that behavior is correct when you attempt to run a ratio that is unworkable for that CPU Default FSB (333) and 1600Mhz DRAM.

 

For 1600Mhz DRAM to work correctly in that board, you must have a 400Mhz FSB processor. You will only find 1333Mhz with a 333Mhz FSB Processor. Otherwise you must overclock your CPU to 400Mhz FSB to enable 1600Mhz on the DRAM.

 

Here is a 101 page thread for people with your motherboard.

 

http://www.xtremesystems.org/forums/showthread.php?t=166289

 

CPU-z SPD are settings to allow your system to read from SPD and set to JEDEC values of which 1333Mhz is the highest and stated by max bandwidth (JEDEC).

 

Any DRAM speed higher than 1333Mhz must be set to extended settings, or set to the XMP characteristic, but still, you MUST have the proper CPU to DRAM ratio and with 1600Mhz DRAM, that MUST be 400Mhz or greater BUS speed. Look at your CPU-z extended XMP profiles and you will see the extended values.

 

 

So, to clarify, to access the 1600Mhz speed of the DRAM you MUST set your CPU to 400Mhz on the FSB. ie.

 

Memory Configuration = Non-ECC

Performance Memory Profiles = Manual - User Defined

Reference Frequency = 400
Memory Frequency = 1600
tCL = 7
tRCD = 7
tRP = 7
tRASmin = 20
Memory Voltage = 1.80v