[SOLVED] Why the clock speed differs

satimis · 12-11-2012, 03:48 AM

Hi all,

This is a newly built PC with following config

AMD 8-core FX-8150 CPU
Motherboard ASUS M5A97R2.0
Video card ASUS HD6450 Silent 1GB DDR3
Hard Disk WD 2TB Black Series
RAM Kingston HyperX KHX1600C10D381K2/16G (2x8G) (Blue Memory)
OS Ubuntu 12.04 desktop 64bit

Installation w/o problem. PC is now working.

$ 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      DIMM Synchronous [empty]
/0/2c/1                         memory      8GiB DIMM DDR3 Synchronous 1333 MHz 
/0/2c/2                         memory      DIMM Synchronous [empty]
/0/2c/3                         memory      8GiB DIMM DDR3 Synchronous 1333 MHz

Showing the RAM speed is 1333 NOT 1600?

ASUS M5A97 R2.0 Specification
http://www.asus.com/Motherboards/AMD...specifications

Kingston HyperX KHX1600C10D381K2/16G (2x8G) (Blue Memory)
http://www.kingston.com/us/memory/hyperx/blu

The RAM sticks are inserted on slot-1 and slot-3
(counted from the Power Supple Connectors-socket)

Did I make mistake here? Pls advise. TA

B.R.
satimis

H_TeXMeX_H · 12-11-2012, 06:15 AM

I would not trust that output, go into the BIOS settings and make sure that it is running at this frequency.

satimis · 12-11-2012, 08:35 AM

Quote:

Originally Posted by H_TeXMeX_H

I would not trust that output, go into the BIOS settings and make sure that it is running at this frequency.

I got it.

On BIOS
Memory Frequency - Auto

change "Auto" -> "DDR3 1600"

Thanks

notsure · 12-11-2012, 08:16 PM

If that is new, you should have went with the FX8320 because it is much improved. Performance and power consumption.

Anyways, the memory timings may be off. I'd suggest you run memtest and make sure the timings are as specified by Kingston. The easiest way to see the timings is by running memtest. However, this is how I see them in linux: http://forums.gentoo.org/viewtopic-t...s+latency.html

satimis · 12-12-2012, 02:25 AM

Quote:

Originally Posted by notsure

If that is new, you should have went with the FX8320 because it is much improved. Performance and power consumption.

FX8320 is still not available here. I have been waiting for >1 month.

Quote:

Anyways, the memory timings may be off. I'd suggest you run memtest and make sure the timings are as specified by Kingston. The easiest way to see the timings is by running memtest. However, this is how I see them in linux: http://forums.gentoo.org/viewtopic-t...s+latency.html

Would it be possible running memtest on Live USB, Fedora/Debian? I don't have DVD/CD ROM/Writer on this PC. Otherwise I'll follow;
Linux] HOWTO: Boot Memtest on USB Drive
http://forum.canardpc.com/threads/28...t-on-USB-Drive

creating memtest on USB. Thanks

B.R.
satimis

satimis · 12-12-2012, 07:49 AM

Hi all,

I ran the memtest on Grub to do the job with pass and no error resulted. It took >1 hour to complete.

Furthermore if adding another 16G (2x8G), DDR3 1600, do I need sticking to the same brand, Kingston? OR I can add another pair from other makers?

Thanks

B.R.
satimis

Air-Global · 12-12-2012, 08:35 AM

When adding memory best is always the same memory type/brand/timings/clock/voltage

When any or multiple of these are off the results are unpredictable. It may work, but no one can be sure untill you put it in and test it.
I would recommend buying exactly the same, or a new complete set.

satimis · 12-12-2012, 08:55 AM

Quote:

Originally Posted by Air-Global

When adding memory best is always the same memory type/brand/timings/clock/voltage

When any or multiple of these are off the results are unpredictable. It may work, but no one can be sure untill you put it in and test it.
I would recommend buying exactly the same, or a new complete set.

Thanks for your advice.

satimis

H_TeXMeX_H · 12-12-2012, 09:48 AM

In order of importance:

type (obviously), frequency, timings, brand

Brand is least important, but you may want to get the same brand if you can.

273 · 12-12-2012, 10:15 AM

I've a feeling if you fill those other two slots your memory speed goes down to 1333? Though that may just be my Motherboard and I can't check as I'm at work.

satimis · 12-12-2012, 10:20 AM

Quote:

Originally Posted by H_TeXMeX_H

In order of importance:

type (obviously), frequency, timings, brand

Brand is least important, but you may want to get the same brand if you can.

Hi,

Where can I find "timings" of RAM, e.g. 7-7-7-21, 9-9-9-27 for DDR3.?

Just checked the packing box of Kingston RAM and couldn't find any things related.

satimis · 12-12-2012, 10:30 AM

Quote:

Originally Posted by 273

I've a feeling if you fill those other two slots your memory speed goes down to 1333?

Pls explain WHY. ASUS M5A97R2.0 supports up to DDR3 1833 32G

My plan is choosing Corsair 4x8G 1600 sets, dualchannel. But the shop which I visited didn't have them. The sales recommended me Kingston DDR3 1600 2x8G, two sets. I haven't used Kingston RAM before. Therefore I only purchased one set first.

H_TeXMeX_H · 12-12-2012, 10:49 AM

Quote:

Originally Posted by satimis

Hi,

Where can I find "timings" of RAM, e.g. 7-7-7-21, 9-9-9-27 for DDR3.?

Just checked the packing box of Kingston RAM and couldn't find any things related.

Yes, those are the timings, see:
http://en.wikipedia.org/wiki/Memory_timings
http://en.wikipedia.org/wiki/DDR3

TobiSGD · 12-12-2012, 11:52 AM

Quote:

Originally Posted by satimis

Pls explain WHY. ASUS M5A97R2.0 supports up to DDR3 1833 32G

That is not really true. Your mainboard, or better the memory controller in your CPU, supports DDR3-1866 and it supports up to 32 GB of RAM.
But not at the same time. AMD supports DDR3-1866 only if there is only one module per channel. Since the CPU has a dual channel interface this means two modules maximum in that machine for that speed and only if you put it in the right slots (one module per channel). When you plug in two modules on the same channel the memory controller will automatically downclock the memory to DDR3-1600, because the load on the bus with two modules is so high that the controller can not sustain the higher clock speed without getting transmission errors.

273 · 12-12-2012, 01:21 PM

Quote:

Originally Posted by TobiSGD

That is not really true. Your mainboard, or better the memory controller in your CPU, supports DDR3-1866 and it supports up to 32 GB of RAM.
But not at the same time. AMD supports DDR3-1866 only if there is only one module per channel. Since the CPU has a dual channel interface this means two modules maximum in that machine for that speed and only if you put it in the right slots (one module per channel). When you plug in two modules on the same channel the memory controller will automatically downclock the memory to DDR3-1600, because the load on the bus with two modules is so high that the controller can not sustain the higher clock speed without getting transmission errors.

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). Can't check what speed mine is running at, sadly, as my PSU died.
Being at work I didn't have time to look up whether it was a limitation of the Motherboard or CPU.