Memory XMP at AMD Motheboard

zumm

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May 27, 2006
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I have a:

AMD A8-3850
Gigabyte A75M-UD2H
Kingston KHX1600C9D3T1K2/8GX


According to the article:
http://www.tomshardware.com/reviews/corsair-vengeance-crucial-ballistix-kingston-hyperX,2907-7.html

In the latency section, my ram is rated at 8-9-8-10 timings with DDR3-1866 at 1.60V

I want to achieve that config, but since my motherboard doesn't read XMP profile.

DDR3 Timings inside BIOS:

[01T/02T] 1T/2T Command Timming
[05T~14T] CAS# Latency
[05T~14T] RAS to CAS R/W Delay
[05T~14T] Row Precharge Time
[15T~36T] Minimum RAS Active Time
[04T~08T] TwTr Command Delay
[90ns~350ns] Trfc0 for DIMM2, DIMM4
[90ns~350ns] Trfc1 for DIMM1, DIMM3
[05T~16T] Write Recovery Time
[04T~08T] Precharge Time
[20T~54T] Row Cycle Time
[04T~08T] RAS to RAS Delay
[16T~40T] Four Bank Activate Window

If I leave them Auto, it sets very high timings and RAM doesn't work so I need to set all timings manually.

Any idea how to obtain suck detailed specs?

Kingston DataSheet for the modules are useless.
http://www.valueram.com/datasheets/KHX1600C9D3T1K2_8GX.pdf
 
Solution
The RAM is Rated DDR3-1600 9-9-9-27-2N (CAS-TRCD-TRP-TRAS-CMD)at 1.65V, but there no reason that you cannot OC the RAM. Sure try to OC it.

However, the kit you linked in Tom's, 'G.Skill Ripjaws X F3-12800CL7D-8GBXH', is a Rated DDR3-1600 CAS 7-8-7-24-2N @ 1.60v which has a superior IC.

GA-A75M-UD2H (rev. 1.0) - http://www.gigabyte.com/products/product-page.aspx?pid=3928#sp
Support for DDR3 2400(OC)/1866/1600/1333/1066 MHz memory modules (Note 2)
(Note 2) The 1866 MHz memory speed is supported only when one or two DDR3 1866 MHz DIMMs are installed. It is not supported when four DIMMs are installed. (Dual channel memory mode must be enabled when installing two DIMMs.)

A8-3850 AD3850WNZ43GX -...
The tom's article you posted was overclocking and comparing ram. But the ram is rated at 1600 9-9-9-27 1.65v, it says that on the datasheet. You can also download cpuz and it'll tell you the other profiles for the ram. XMP is an intel thing, you have to manually set it if it doesn't work, but usually it defaults to the correct specs.
 
The RAM you have is designed for Intel i7 CPUs, not AMD. See the upper right corner of the technical data sheet.

Only Intel mobos read XMP RAM profiles, not AMD CPUs.

The RAM you have has a default frequency of 1333 MHZ. @ 1.5v. It was tested and able to be OC'ed to 1600 MHz. @ 1.65V on an Intel i7 mobo. That does not however guarantee that it will run at 1600 MHz. on YOUR AMD mobo/APU let alone @ 1866 MHz. which your APU may be capable of.

All you can do is try to get it to work. Otherwise you need to purchase the correct AMD approved 1866 MHz. RAM for your APU.
 
The RAM you have, according to it's naming is a 1600 CAS 9 /second param in BIOS which is most significant timing/, 1 T /first param/. Not sure for the rest /D3 and K2/, but you should check the specs sheet - there's what is what, and most of the things you shouldn't touch /and don't actually need to/. So CAS 9 and T=1 should be your default parameters set auto by the BIOS. The only thing that really may matter something is changing the CAS latency to 8 /and of course the frequency/ but success is not guaranteed, depends on both the RAM and the Mobo and needs experimenting. Usually achieving better OC results comes with slightly rising the voltage, but you should be very careful with that one and if you don't know what you are doing better don't touch it, you may burn your modules.
 
The RAM is Rated DDR3-1600 9-9-9-27-2N (CAS-TRCD-TRP-TRAS-CMD)at 1.65V, but there no reason that you cannot OC the RAM. Sure try to OC it.

However, the kit you linked in Tom's, 'G.Skill Ripjaws X F3-12800CL7D-8GBXH', is a Rated DDR3-1600 CAS 7-8-7-24-2N @ 1.60v which has a superior IC.

GA-A75M-UD2H (rev. 1.0) - http://www.gigabyte.com/products/product-page.aspx?pid=3928#sp
Support for DDR3 2400(OC)/1866/1600/1333/1066 MHz memory modules (Note 2)
(Note 2) The 1866 MHz memory speed is supported only when one or two DDR3 1866 MHz DIMMs are installed. It is not supported when four DIMMs are installed. (Dual channel memory mode must be enabled when installing two DIMMs.)

A8-3850 AD3850WNZ43GX - http://www.cpu-world.com/CPUs/K10/AMD-A-Series%20A8-3850%20AD3850WNZ43GX%20(AD3850WNGXBOX).html
The fastest supported memory is DDR3-1866

CPU: | blank | 4GB | blank | 4GB |
BIOS:
Load Optimized
Set Memory Clock -> 8 ; 8 x 200 = 1600 or OC 9.33 x 200 = 1866 **
DRAM Configuration / Enter
DDR3 Timing Items -> Manual ; IF 'Quick' is available use that option.
1T/2T Command Timing -> 2
CAS# latency -> 9 ; see **
RAS to CAS R/W Delay -> 9 ; see **
Row Precharge Time -> 9 ; see **
Minimum RAS Active Time -> 27 ; see **

DDR3 Voltage Control -> 1.64v ; closet value to 1.65v

Save & Exit = Yes

**IF attempting to OC your RAM to DDR3-1866 1st try 10-10-10-30-2N (CAS-TRCD-TRP-TRAS-CMD) @ 1.65v. There's no guarantees OC'ing above spec.
 
Solution
BTW - Most ALL RAM has an Intel XMP 'SPD' it doesn't mean the RAM won't run on AMD, it only means the AMD MOBO BIOS won't read the XMP data and instead uses JEDEC data as noted in CPU-z 'SPD'.

To optimize the RAM set the Frequency, CAS and Voltage manually. IMO it's best to use RAM that is optimized for the AMD platform. Therefore look at the QVL lists or RAM manufacturer's website and if possible search for supported kits for your MOBO.
 
Thanks for the replays,

I had a hard time setting the values at bios, so I'm posting them in case someone needs them:

[01T] 1T/2T Command Timming
[09T] CAS# Latency
[09T] RAS to CAS R/W Delay
[09T] Row Precharge Time
[27T] Minimum RAS Active Time
[05T] TwTr Command Delay
[160ns] Trfc0 for DIMM2, DIMM4
[160ns] Trfc1 for DIMM1, DIMM3
[10T] Write Recovery Time
[05T] Precharge Time
[33T] Row Cycle Time
[04T] RAS to RAS Delay
[16T] Four Bank Activate Window

1.6v 1600Mhz

I couldn't get it to 1866Mhz stable.

Cheers