memory overclock question for an A10-6700

[William Gaatjes]

I have a question, i would like to only overclock the memory bus of my APU.
Maximum official memory clockspeed for A10-6700 is 1866MHz.
However, the A10-6800 can go up to 2133MHz.

Let's say i buy DDR3-2133MHz specified memory.
Is it possible to overclock the memorycontroller only of the A10-6700 ?
And get stable long lasting results ?
Has anybody tried this ?

 

[William Gaatjes]

Officially the A10-6700 does not support 2133MHz.
For now i want to get the best out of my memory that i have within the specifications. The motherboard is a model from Gigabyte : GA-F2A75M-HD2 (rev. 1.0).
I bought a set of two of these (2x 4GB DDR3-1833MHz):
GEL38GB1866C9DC - CL9 10-9-28.
But these are XMP timings.

Specifications :
http://www.geil.com.tw/products/show/id/390
http://www.geil.com.tw/products/showSpec/id/390

My memory is a 2x4GB model. It is an XMP model but it will not run at 1866MHz while it is rated at 1866MHz. When i enable the XMP setting in my bios, the timings are tighter as can be seen in my screendumps. But the memory clock does not change, it remains at 1600MHz. If i change it manually to 1866MHz, my bios comes with a screen explaining that there was a settings error and the the default bios settings have been loaded. I also tried the AMP memory profile setting in the bios but that did nothing. I tested the XMP setting (with 1600MHz clock) with memtest 4.3.2. and it seemed to function , at least for 20 minutes it did. When i set the timings at default and the memory clock at 1866MHz, i get the same error as above and my pc reverts back to 1600MHz.

My memory at XMP settings :

My memory at default settings :

My apu running at full speed :

Why does it not work ?
Can anybody give some good advice or is the memory just not good ?

 

[William Gaatjes]

Also, when my bios reads the XMP timings, the timings are different from XMP spec stored in the spd eeprom. Why ? Is this common ?

 

[William Gaatjes]

Is it common that the web site specification says 1,65V memory voltage and the SPD says 1,5V memory voltage ?
I assume that my memory cannot run at 1866MHz @ 1,5V.
I have to buy other memory i guess and sell this memory...:\

 

[William Gaatjes]

This is strange but i got it working.
I entered the timings manually to 11-11-12-28. And set manually the memory clock to 1866MHz. I let memtest 4.3.2 run for an hour, waiting for at least one complete pass and it did without errors.

Why does the bios failed to boot at auto with the same timings but works with those same timings when entered manually ?
I am happy.
Now i can try to tighten the timing settings for optimal results.
At least now i have the full bandwidth the apu supports available.

Does anybody have an explanation for me ?

 

[William Gaatjes]

Now i have to read that Anandtech article about memory timings again. :biggrin:

http://www.anandtech.com/show/3851/...now-about-sdram-memory-but-were-afraid-to-ask

 

[monstercameron]

why are you discussing this with yourself? o.0

 

[William Gaatjes]

I am not discussing it with myself. I am just posting progress and hoping for an answer why.

 

[William Gaatjes]

YaY ! :biggrin:

I tightened the timings and ran another memtest 4.3.2 and it passed.

Now my apu is running at maximum memory clock of 1866MHz with timings thighter then my default timings at 1600MHz.

I had to do some reading though...
http://www.hardwaresecrets.com/article/Understanding-RAM-Timings/26/1
http://en.wikipedia.org/wiki/Memory_timings

 

[Erenhardt]

set it to 1,65V and try 2133 or even 2400 MHz

 

[William Gaatjes]

set it to 1,65V and try 2133 or even 2400 MHz

I do not want to fry my apu. I am afraid it will get damaged. If it was just a test system i would try it with some caution. But this system is my main system. It has to be reliable and i use it within the specifications, so i hope it will not fail on me.

 

[monstercameron]

I do not want to fry my apu. I am afraid it will get damaged. If it was just a test system i would try it with some caution. But this system is my main system. It has to be reliable and i use it within the specifications, so i hope it will not fail on me.

dont these mobos have over voltage protection?

 

[William Gaatjes]

dont these mobos have over voltage protection?

I have no idea.
It has an extreme amount of settings even just for memory alone.
I can adjust about 20 parameters that have something to do how the memory is addressed. I just kept it with the 5 most common as can be seen by the screenshots. The CPU settings are also a screen full of settings. If you like tweaking, this motherboard from Gigabyte is the one you want. It has a modern bios that supports mouse and usb keyboards and has a 3D view mode. Bootmenu option, backup mode with a dual bios system. It does not hang when you adjust settings to vigorously, instead it comes up with a screen that the settings were wrong and that the default settings have been loaded. And then comes with an option to go to the bios or just continue booting.

 

[Erenhardt]

I pushed my Adata 1600 1,5V to 1,65V and it didn't even increase temperatures noticeably. I think any DDR3 can take up to 1,65V.
But do as you whish

 

[William Gaatjes]

I pushed my Adata 1600 1,5V to 1,65V and it didn't even increase temperatures noticeably. I think any DDR3 can take up to 1,65V.
But do as you whish

I am afraid that my DDR3 memory can handle it but my apu cannot.
I do not want to fry my apu. :\

 

[alawadhi3000]

Also, when my bios reads the XMP timings, the timings are different from XMP spec stored in the spd eeprom. Why ? Is this common ?

Thats because some RAM have more than one XMP profile stored in them, maybe your motherboard is only seeing the first profile.

 

[William Gaatjes]

Thats because some RAM have more than one XMP profile stored in them, maybe your motherboard is only seeing the first profile.

I can only select one profile in the bios. That might be the case.

 

[Erenhardt]

As far as I know increasing memory voltage changes only operating voltage of DDR sticks. Memory controller and any other CPU part is operating on its own voltage which is way lower.

Check if you have the latest bios for you motherboard.

 

[William Gaatjes]

As far as I know increasing memory voltage changes only operating voltage of DDR sticks. Memory controller and any other CPU part is operating on its own voltage which is way lower.

Check if you have the latest bios for you motherboard.

But are the voltage input/output levels on the memory data bus and address bus not dependent on the voltage applied to the memory and the apu ? I would expect both the memory sticks and the memory section of the APU to run at the same voltage because of the i/o voltage levels of the address bus and the data bus.

 

[William Gaatjes]

I just found out there is a rev3.0 version of this board with a FM2+ socket meaning that for around ~50 euro one can buy this board with support for kaveri and for older FM2 APU's such as richland.

GA-F2A75M-HD2 (rev. 3.0)

http://uk.gigabyte.com/products/product-page.aspx?pid=4759#ov

For my MB GA-F2A75M-HD2 (rev. 1.0) There is an update, but it is a beta bios. Since i have no issues, i will keep the bios F4 for now.

 

[Erenhardt]

But are the voltage input/output levels on the memory data bus and address bus not dependent on the voltage applied to the memory and the apu ? I would expect both the memory sticks and the memory section of the APU to run at the same voltage because of the i/o voltage levels of the address bus and the data bus.

No. These are separate. But even if we assume those are on the same voltage, kaveri can run with 1,65V 2133MHz memory sticks without any problems. Increasing memory voltage and memory frequency to that value should not make any damage to the APU. As long as DDR sticks are ok with the voltage, everything should be ok. I've seen DDR3L 1,35V pushed to 1,65V - no problem.

Where did you get a8-7600? From what I know it is not out yet.

From wiki:

According to JEDEC,[2] 1.575 volts should be considered the absolute maximum when memory stability is the foremost consideration, such as in servers or other mission-critical devices. In addition, JEDEC states that memory modules must withstand up to 1.975 volts before incurring permanent damage, although they are not required to function correctly at that level.

EDIT: I misread the 6700 as 7600 my bad

 

[William Gaatjes]

If i could get my hands on the datasheet of my A10-6700, i could verify that the apu memory controller can handle 1,65V. But i have not been able to find one. To be honest, i have not seen a datasheet about x86 processor in years. I do not have a kaveri but a richland. It does seem faster, when encoding mp3's , my pc seems a bit faster now. Too bad there is no free aida64 version.
I would like to benchmark my apu.

 

[alawadhi3000]

For my MB GA-F2A75M-HD2 (rev. 1.0) There is an update, but it is a beta bios. Since i have no issues, i will keep the bios F4 for now.

Yeah keep the F4 BIOS, the F5B only adds support for some newer CPUs.