[SOLVED] Why the clock speed differs

TobiSGD · 12-12-2012, 02:04 PM

Quote:

Originally Posted by 273

Ah, is it 1600 it's supposed to downclock to? I just checked my CPU box and I've the 8120, so perhaps mine starts at 1600 and slows to 1333 when 4 mudules are installed (as I have).

All AMD FX CPUs support DDR3-1866 and downclock to DDR3-1600 whith two modules on one channel, regardless of the model. If you run your memory at 1600MHz anyways there is no downclock needed and the memory controller will not downclock.

This is different with the Phenom II CPUs, they support DDR3-1600 and downclock to DDR3-1333 whith two modules on a channel.

273 · 12-12-2012, 02:16 PM

Quote:

Originally Posted by TobiSGD

All AMD FX CPUs support DDR3-1866 and downclock to DDR3-1600 whith two modules on one channel, regardless of the model. If you run your memory at 1600MHz anyways there is no downclock needed and the memory controller will not downclock.

This is different with the Phenom II CPUs, they support DDR3-1600 and downclock to DDR3-1333 whith two modules on a channel.

Thanks, when I get a new PSU I'll know to ensure my memory is set as fast as possible.

273 · 12-16-2012, 07:12 AM

I just checked and my RAM is set at 1333MHz, when I tried to set it to 1600MHz the PC wouldn't boot at all and I was forced to clock it down. That's using all 4 slots though with an FX 8120 on a Gigabyte GA-990XA-UD3 motherboard.
I wish now I had bought 2 x 8GB modules rather than being a cheapskate and using 4 x 4GB modules.

TobiSGD · 12-16-2012, 07:22 AM

Make sure you have set the correct timings and voltages, the clockspeed is only one part of the equation, all other settings also have to match the spec of your RAM.

satimis · 12-16-2012, 08:43 AM

Quote:

Originally Posted by TobiSGD

Make sure you have set the correct timings and voltages, the clockspeed is only one part of the equation, all other settings also have to match the spec of your RAM.

Hi,

According to;
http://www.kingston.com/us/memory/hyperx/blu

Spec

Code:

==== 
blu - 16GB Kit (2x8GB) - DDR3 1600MHz CL10 DIMM

Part Number: KHX1600C10D3B1K2/16G

HTS: 8473.30.1140, ECCN: EAR99

Specs: DDR3, 1600MHz, CL10, 1.5V, Unbuffered, Spec Sheet PDF

Timings: 1600MHz, 10-10-10, 1.5V

On BIOS - settings:

Code:

Memory Frequency - DDR3-1600MHz
DRAM CASH Latency - 10 (factory "auto")
DRAM RAS# to CAS# Delay - 10 (factory "auto")
DRAM RAS# PRE Time - 10 (factory "auto")

Voltage - 1.5v (factory "auto")

$ sudo lshw -short -C memory

Code:

H/W path      Device      Class       Description
=================================================
/0/0                      memory      64KiB BIOS
/0/4/5                    memory      384KiB L1 cache
/0/4/6                    memory      8MiB L2 cache
/0/4/7                    memory      8MiB L3 cache
/0/2c                     memory      16GiB System Memory
/0/2c/0                   memory      8GiB DIMM DDR3 Synchronous 1600 MHz (0.6 ns)
/0/2c/1                   memory      DIMM Synchronous [empty]
/0/2c/2                   memory      8GiB DIMM DDR3 Synchronous 1600 MHz (0.6 ns)
/0/2c/3                   memory      DIMM Synchronous [empty]

Why "DIMM Synchronous [empty]" ?

satimis

273 · 12-16-2012, 08:47 AM

You have 4 memory slots but are using two of them or you have two slots but the chipset can handle 4?

satimis · 12-16-2012, 09:52 AM

Quote:

Originally Posted by 273

You have 4 memory slots but are using two of them or you have two slots but the chipset can handle 4?

There are 4 memory slots. Now I only use two of them. I'll add another set later.

satimis

TobiSGD · 12-16-2012, 09:52 AM

As 273 said, you use 2 modules on a mainboard with four slots, which obviously leaves two slots empty.

satimis · 12-16-2012, 10:16 AM

Quote:

Originally Posted by TobiSGD

As 273 said, you use 2 modules on a mainboard with four slots, which obviously leaves two slots empty.

Ah, I see.

Code:

/0/2c/1    memory      DIMM Synchronous [empty]
/0/2c/3    memory      DIMM Synchronous [empty]

are empty slots.

Any other data in respect of RAM I have to set on the BIOS?

Thanks

satimis

TobiSGD · 12-16-2012, 10:21 AM

Quote:

Originally Posted by satimis

Any other data in respect of RAM I have to set on the BIOS?

No, seems that you run your RAM exactly as intended.