AMD CPU needs more DRAM Voltage for "Low Voltage" memory

[c3k]

Gents,

I'm doing a new build. The mobo is an Asus M5A88-M with a Phenom II x3 720 BE.

The mobo is a mATX. I want to minimize heat/cooling needs, so I was happy to find some G. Skill memory labelled "Low Voltage". Cool. Before I bought it, I wanted to verify that it was compatible with the specific mobo listed.

The memory is: F2-12800CL9D-8GBSR2. It is a 2x4GB pair.

I was told it was compatible.

It was not.

The machine would not post. Substituting in my trusty backup G. Skill memory (a different 2GB card) the mobo POSTed right up.

In order to get a refund through Newegg, they're charging me a restocking fee. Very uncool.

I would not have purchased this 1.25v memory is I hadn't received email confirmation from G. Skill that it would work.

Soooo. Since it won't even POST, I can't do anything with the memory/timings/voltages. Before I'm out 7 1/2 bucks, does anyone have any (helpful) suggestions?

(Hey, G. Skill, if we can't get it to work, do you mind sending me the restock fee?)

Thanks,
Ken

[c3k]

Just to be clear: I relied on G. Skill tech support email to verify whether it was compatible. I didn't go browsing forums or websites. I contacted G. Skill directly. Grrrrr. It was based on their "okay" that I purchased it from the egg.

[Tradesman]

Off hand I would say they are compatible with the mobo, and this comes up all to often with AMD boxes, the problem may well lie with the CPU, even w/ the 4th core unlocked on your 720, it's still going to take a rather healthy OC to even think of attempting 1600 sticks, might have a better shot w/ 1333. Will need increases on vCore, CPU/NB and even DRAM voltage. To truly minimize heat and cooling needs you'd need to run the CPU at stock speed and with CPU rated sticks, I believe the 720 calls for 1066 sticks but not positive. Generally I normally recommend a minimum of a 965 Rev C if wanting to run 1600 and up sticks, which basically even requires an OC and therefore more heat..

[c3k]

Tradesman,

You're correct in your analysis...if I had been trying to do any of that. I was not. This was a totally raw, fresh, new build. I was not trying to unlock the 4th core. I was not trying to OC the CPU. I was not trying to run the memory at a speed beyond the motherboard's rated speed (the memory is rated at 1600; mobo stock is 1333).

I hadn't even been able to get the motherboard to POST, let alone start changing any settings in the BIOS.

My steps:
Install motherboard in case.
Install CPU in motherboard.
Install memory in motherboard.
Install all the other hardware (hard-drive, DVD drive, etc.)

Turn on power.

Motherboard green power light illuminates.
Motherboard red "DDR error" light illuminates and stays illuminated.
Monitor never even flickers.

Spend an hour swapping 2 memory sticks through 4 risers, using every combination possible. The computer never POSTs.

Stick a known, good, memory stick in. Ripjaws to the rescue! The computer POSTs and the world is good. Install OS.

Hmmm.... let's try the 1.25v memory again... Repeat all the above steps. Repeat all the above outcomes.

At no point did I try to overclock or unluck or overspeed any component.

The ASUS M5A88-M, an AMD 880G/850SB motherboard, will not POST with either, or both, of the 1.25v memory sticks installed.

[c3k]

Update: ASUS to the rescue

Update: I got it to POST with the 1.25v memory stick. Go figure...

Next to the red LED which signifies a bad memory check prior to POST, ASUS conveniently placed a small microswitch. It is labelled "MemOK". The manual says to press it if the LED is red and that will begin an autotune for the memory. I tried that. The LED flashed, as it was supposed to, but then returned to steady red, with no POST. I pressed again. The same. I pressed a third time, and like a geni from a lamp, after the third try, it POSTed!

I went into the BIOS to see what it had come up with. To successfully POST with one stick of 1.25v rated memory, 4GB, it used 1.60 volts! Hmmm, I manually dropped the voltage to 1.25. (The standard is 1.5v.) I rebooted. It POSTed. That was weird. I added the second memory stick into the appropriate riser. It POSTed.

With the BIOS set to auto, meaning 1.5v, it would not POST. It autotuned to 1.6 volts and worked. I then manually changed it to the rated 1.25 volts and it POSTed.

I am confused (I didn't see what happened to timings...That may be the key to the POST.), but the computer is running with the memory.

Ken

[Tradesman]

Check the speed and timings, prob booted to 1066 or 1333, whichever the default is. I'd write down the timings, voltages, etc.....then if you want to try 1600, see the sticky:

http://www.gskill.us/forum/showthread.php?t=7688

[GSKILL TECH]

Low Voltage memory can work with AMD platforms, you just need to use a higher voltage. With the higher voltage, you can use better timings or higher frequency.

Otherwise to operate at exact specifications, it is only tested on the platform the memory was designed for.

Thank you
GSKILL TECH

[c3k]

Low Voltage memory can work with AMD platforms, you just need to use a higher voltage. With the higher voltage, you can use better timings or higher frequency.

Otherwise to operate at exact specifications, it is only tested on the platform the memory was designed for.

Thank you
GSKILL TECH

GSKILL TECH? Is that you? Your voice sounds familiar. Hmmm, are you the GSKILL TECH who emailed me and said it was compatible? Now, before we all get our danders up, the memory is now working (rated 1.25v, will only POST at 1.6v) at 1333, rated numbers all the rest of the specs (9-9-9-24, etc.).

You guys give great timing/adjustment, etc., advice. It's usually spot on. For the record, if you didn't know if it would work, that answer would've been just as good as "yes" or "no".

The number of mobo/memory combinations must be staggering. Toss in users of varying abilities, and it's amazing how well it all works. Now, if someone says, "I have this mobo. Will this memory work?" A response of "That's never been tried. We think it should. However, low voltage modules usually have a need for extra-high voltage (approx. 3.76v), in order to work with most AMD 850 Southbridge mobos", would've been OUTSTANDING. Adding in, "We suggest you use a 1.5v module, unless you feel invincibly superior as a builder" would've won you top marks. Top. Very top.

The above is written in a light-hearted manner. However, do not mistake light-hearted for joking. I sincerely wish a lesson is learnt. I know I have taken something away from this experience.

Thanks,
Ken

[Tradesman]

What you bring up is a gripe I've had, for what seems forever although it's basically only been the last half dozen years. Mobo makers and DRAM manufacturers both (in all seriousness) test as many combos as they can in the time they have and with the Memory or the mobos they have available, which is good and I applaud them for that......what I wish if they would be more forthcoming with how they rigs are tested - which generally is with the fastest, most powerful applicable (AMD or Intel) CPU. Most people don't A) know this and B) Don't realize what it means........they look at a mobo and it's advertising and see things like it will run 16GB and the DRAM speed is up to 2000 or 2133......Now them we get to the real problem, (not so much with Intel) but with AMD of current available CPUs, they have ones that can only run up to 1066 at 1 stick per channel, others, again only 2 sticks total at 1333 (so a max of 8GB), many won't run 1600 at at all, others will but at the expense of requiring high voltages which means more heat, others will run faster DRAM but again only 2 sticks, etc, etc, etc. i.e. using your board as an example which advertises 16GB and fastest at 2000 the only thing tested at 2000 is a single DIMM, so you'd be limited to 4GB, at 1866 they show up to 4 DIMMs, but at 2GB per DIMM, and they only show a single 1600/16GB set, but interestingly enough they also show a 4 stick 16 GB/1333 set, but it's only identified as able to use two sticks, they also show a 24 GB set (which is a six stick set) as using 4 sticks (gives you an idea about what I was saying, testing with whatever is available)....anyway soory to gripe about my gripe, but I think it's a dis-service to customers, but driven by the dollar, the mobo makers maximize possible settings in their advertising and more often than not tell people - 'Oh well', when somebody buys 16GB of 'qualified' DRAM yet the CPU they buy won't drive those sticks.

[GSKILL TECH]

c3k,

No problem, we will try to make it more clear in the future. If you would like, we can exchange for a different kit. We may have failed to disclose that information as generally a low voltage kit can achieve better specifications at standard (higher) voltage, so that isn't too bad. In addition, your CPU plays a large role, so it is difficult to know what results of the whole combination may be. For all we know a BIOS update/different CPU can support a lower voltage.

Lastly, the memory is stated for Intel, and if the rated speciifcations were capable for an AMD platform, we would list it for AMD as well.

Thank you
GSKILL TECH

[c3k]

I appreciate the response. Really. Even more, I appreciate the offer to swap my kit out. I've given your offer some thought, and yes, I'd like to exchange it.

I bear the responsibility for my purchase decision. It was a non-standard voltage and I obviously had reservations about it, which is why I contacted G. Skill Tech Support before purchasing. That's on me.

I purchased it through a large on-line retailer. Their name rhymes with "do-beg". (Their RMA policy, in this case, included the restocking fee I alluded to in my first post. Grrr.)

You, G. Skill, were outside the "purchase loop". Your offer to exchange it shows the outstanding service which you're famous for.

The reason I'd like to take you up on this offer, follows. The machine has BSOD'ed twice. (The CPU was used in a previous build and was stable.) I suspect the memory. I flashed the BIOS to the latest, 0505, and had GREAT difficulty getting the mobo to POST. The MemOK switch did not work. I had to pull my memory out of another machine to POST, then boost the BIOS memory voltage to 1.6, reswap memory, then it POSTed. Memory issue again. It is stable now, but I imagine I'll have issues in the future.

What remains are the details of how to conduct this exchange. I'm all ears.

Thank you, very much, for the offer. (How can edit the title of this thread?)

Regards,
Ken

[GSKILL TECH]

Contact the RMA dept and let them know which kit you would like to exchange for. They will respond back with details.

http://www.gskill.com/rma.php

Meanwhile, I have made the title more clear. You should be able to edit it in the "Advanced" section of editing your first post.

Thank you
GSKILL TECH

[c3k]

Thanks, I will contact them.

I am at a disadvantage in deciding which kit would be a good replacement. Are there any that you would recommend, given this thread, with similar specs, having a capacity of 8GB in a total of 2 sticks (2x 4GB)?

Thank you for your help!

Ken

[GSKILL TECH]

With that CPU you are limited, so I would suggest sticking with something like F3-12800CL8D-8GBRM or F3-12800CL7D-8GBRH

Thank you
GSKILL TECH

[c3k]

With that CPU you are limited, so I would suggest sticking with something like F3-12800CL8D-8GBRM or F3-12800CL7D-8GBRH

Thank you
GSKILL TECH

Ahhh, I should've revealed THE PLAN to you, first. The only reason the 720 is in there, is that CPU was going unused. My other AMD machine has a 1090T in it. THE PLAN requires me to put a Bulldozer in the 1090T, and then replace the 720 with the 1090T. THE PLAN is quite clear on that.

So, now that the upgrade path has been revealed, which 2 stick kit would you recommend to have 8GB of memory which would not unduly hold back a 1090T? Which would you recommend to support a moderate overclock of a 1090T? THE PLAN allows for flexibility: I may end up putting a Bulldozer into this Asus M5A88-M mobo.

Thanks,

Ken