Kingston 1600CL9@1.65V as 1333@1.5V

[Guest]

Hi, i recently bought a 8GB Memory Kit from Kingston (KHX1600C9D3K2/8GX - 1.65V), not knowing that the Ivy-IMC has a 1.5 - 1.57V limit. As i dont wan't to damage my IMC, i try to use the RAM with 1333MHz @ 1.5V. For this, i changed the DRAM-Voltage to 1.5V and 9-9-9-25 at the UEFI. Cpu-z now shows the following at SPD:

DIMM # 1
SMBus address 0x51
Memory type DDR3
Module format UDIMM
Manufacturer (ID) Kingston (7F98000000000000)
Size 4096 MBytes
Max bandwidth PC3-10700 (667 MHz)
Part number KHX1600C9D3/4GX
Serial number 25267F3B
Manufacturing date Week 25/Year 12
Number of banks 8
Nominal Voltage 1.50 Volts
EPP no
XMP yes
XMP revision 1.2
JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
JEDEC #1 6.0-6-6-17-23 @ 457 MHz
JEDEC #2 7.0-7-7-20-27 @ 533 MHz
JEDEC #3 8.0-8-8-22-30 @ 609 MHz
JEDEC #4 9.0-9-9-25-34 @ 685 MHz
XMP profile XMP-1600
Specification PC3-12800
Voltage level 1.650 Volts
Min Cycle time 1.250 ns (800 MHz)
Min tRP 11.25 ns
Min tRCD 11.25 ns
Min tWR 15.00 ns
Min tRAS 33.75 ns
Min tRC 45.00 ns
Min tRFC 160.00 ns
Min tRTP 7.50 ns
Min tRRD 6.00 ns
XMP timings table CL-tRCD-tRP-tRAS-tRC-CR @ frequency (voltage)
XMP #1 6.0-6-6-18-24-0T @ 533 MHz (1.650 Volts)
XMP #2 7.0-7-7-21-28-0T @ 622 MHz (1.650 Volts)
XMP #3 8.0-8-8-24-32-0T @ 711 MHz (1.650 Volts)
XMP #4 9.0-9-9-27-36-0T @ 800 MHz (1.650 Volts)

DIMM # 2
SMBus address 0x53
Memory type DDR3
Module format UDIMM
Manufacturer (ID) Kingston (7F98000000000000)
Size 4096 MBytes
Max bandwidth PC3-10700 (667 MHz)
Part number KHX1600C9D3/4GX
Serial number 26267C3B
Manufacturing date Week 25/Year 12
Number of banks 8
Nominal Voltage 1.50 Volts
EPP no
XMP yes
XMP revision 1.2
JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
JEDEC #1 6.0-6-6-17-23 @ 457 MHz
JEDEC #2 7.0-7-7-20-27 @ 533 MHz
JEDEC #3 8.0-8-8-22-30 @ 609 MHz
JEDEC #4 9.0-9-9-25-34 @ 685 MHz
XMP profile XMP-1600
Specification PC3-12800
Voltage level 1.650 Volts
Min Cycle time 1.250 ns (800 MHz)
Min tRP 11.25 ns
Min tRCD 11.25 ns
Min tWR 15.00 ns
Min tRAS 33.75 ns
Min tRC 45.00 ns
Min tRFC 160.00 ns
Min tRTP 7.50 ns
Min tRRD 6.00 ns
XMP timings table CL-tRCD-tRP-tRAS-tRC-CR @ frequency (voltage)
XMP #1 6.0-6-6-18-24-0T @ 533 MHz (1.650 Volts)
XMP #2 7.0-7-7-21-28-0T @ 622 MHz (1.650 Volts)
XMP #3 8.0-8-8-24-32-0T @ 711 MHz (1.650 Volts)
XMP #4 9.0-9-9-27-36-0T @ 800 MHz (1.650 Volts)

What concerns me is, that under the actual memory tap i get 9.0-9-9-25-34 @ 667 MHz and not at 685 MHz. Is this a problem, and if so how do i fix it?

Thanks in advance.

 

[rolli59]

I have the same ram running at 1.5volts at 1333MHz which is the default SPD for SB reported by CPU-Z. Only at 1600 it needs 1.65.

 

[Guest]

I know, my question was more why it is running @667MHz, and not @685MHz as supposed by the JEDEC.

 

[rolli59]

667MHz is what mine says and it make 1333MHz which is the default for so many CPU's and motherboards. Why CPU-Z is showing these odd numbers in your case I do not know.
533=1066
667=1333
800=1600

 

[Guest]

So, yours says JEDEC #4 9.0-9-9-25-34 @ 667 MHz on the SPD-Tab as well as on the Memory-Tab? Im just wondering why the MHz-Value for the same timings in the Memory-Tab is not exactly the same than on the SPD-Tab (667 instead of 685).