Choosing RAM

[seekermeister]

no , with the advent of higher buss speeds the stable latency has generally gone up a bit with DDR3 :/

CAS latency will always mean "how many clock cycles the memory module will delay in returning a data requested by the CPU"

Okay, but to put that into perspective, with two qualified RAMS, the one with the lower CAS would be the better performing...right?

Yes. The lower the timings, the better the machine will perform.
Here's an AM3 memory link you might want to read before buying. They suggest the best kit for AM3 is cas 6 1333.
AMD AM3 Memory Performance Guide - Introduction

I scanned over the article, and while they seem to favor the 1333 memory, I didn't see anything that made it stand out as the best choice. Maybe I was scanning too fast.

One thing in those charts that confused me, was their reference to ganged or unganged memory. Does that mean the same thing as dual or single channel memory?

 

[seekermeister]

Just a question but why not newegg? I bet I have done $alot the last year threw them with only 2 or 3 doa's and rma was painless.
Yes the lower the cas is the better chip.

My reasons are personal, and not of interest to many people. They are more a matter of principle, rather than price/service that Newegg provides, therefore I don't care to delve into it.

 

[Fumz]

Okay, but to put that into perspective, with two qualified RAMS, the one with the lower CAS would be the better performing...right?

Yes. The lower the timings, the better the machine will perform.
Here's an AM3 memory link you might want to read before buying. They suggest the best kit for AM3 is cas 6 1333.
AMD AM3 Memory Performance Guide - Introduction

I scanned over the article, and while they seem to favor the 1333 memory, I didn't see anything that made it stand out as the best choice. Maybe I was scanning too fast.

One thing in those charts that confused me, was their reference to ganged or unganged memory. Does that mean the same thing as dual or single channel memory?

Yes, ganged is dual channel, unganged is single channel. In theory, as I understand it, unganged lets each core get it's own stick of RAM. It's an nVidia thing I'm not at all up on.

The thing that made cas 6 1333 stand out as the best choice was all the charts (most of them) showing it performing better... and

Ideally DDR3-1333 memory with CAS6-7 timings would be best

 

[seekermeister]

Yes, now that I look again, I see what you mean, but in all cases, the CAS was lower than with what I have found available so far. Perhaps the edge that the 1333 ram tested CAS would have would also hold true at the higher CAS, but I don't know. With what we have found on the 1600 prices, cost is not really a factor, but there still wouldn't be a good reason to pay more for less. Yet, it still seems that there must be a good reason to opt for the 1600...I don't know...perhaps for those who overclock???

 

[seekermeister]

Fumz,

Yes, ganged is dual channel, unganged is single channel. In theory, as I understand it, unganged lets each core get it's own stick of RAM. It's an nVidia thing I'm not at all up on.

Since this motherboard has an AMD chipset, where does Nvidia come into play?

EDIT: With the hardware that I currently have, there is no option to choose between dual and single channel, it does that automatically, depending on the RAM configuration in use. Has that changed with newer hardware?

 

[Glhs958]

No problem I was just curious but its not really a big deal. Sometimes I learn something new when I ask. Hope I didn't offend in anyway that wasn't the intention.

 

[Fumz]

It's not as straightforward as "more for less" if the idea is that 1333 is "less than" 1600. Yes, 1600 operates at a higher frequency than 1333; however, that does not always mean better performance.
I guess a good question is why are you choosing 1600?

 

[seekermeister]

No problem I was just curious but its not really a big deal. Sometimes I learn something new when I ask. Hope I didn't offend in anyway that wasn't the intention.

No offense at all. The only reason that I don't go into detail, is because I feel that it would be a waste of time for me, and the readers, and it would cause the topic to go off in a tangent from what it is intended for.

 

[Fumz]

Fumz,

Yes, ganged is dual channel, unganged is single channel. In theory, as I understand it, unganged lets each core get it's own stick of RAM. It's an nVidia thing I'm not at all up on.

Since this motherboard has an AMD chipset, where does Nvidia come into play?
EDIT: With the hardware that I currently have, there is no option to choose between dual and single channel, it does that automatically, depending on the RAM configuration in use. Has that changed with newer hardware?

Like I said, I am not at all up on this. I haven't had an AMD since Conroe... but it's my (limited) understanding that this is something like, or taken from, nVidia's linked or unlinked memory setting.

Nothing changed that I'm aware of, but I don't run an AMD. Whether you run single or dual channel still depends on RAM placement, or whether you use a single stick.

What AMD does with ganged and unganged; whether you need 4 sticks to run unganged or can do it with 2; whether or not AMD has fixed the AM3 4 dimm issue... all good questions for an AMD owner, or potential AMD owner.

 

[seekermeister]

It's not as straightforward as "more for less" if the idea is that 1333 is "less than" 1600. Yes, 1600 operates at a higher frequency than 1333; however, that does not always mean better performance.
I guess a good question is why are you choosing 1600?

Again, I'm not choosing the 1600, that is why we are conversing about this. It seemed like a good choice at the outset, simply because it appeared to be higher performing, and was somewhat more available than some RAMs of even higher timings. But, that was the entire intent of this thread, to gain insight into the best choice.

 

[Fumz]

Ah, k... I was confused. Basically you were right: 1600 if you're overclocking, or if you're a little fanatical about performance (however slim those margins may be)/raises hand/; low latency 1333 for all else.

 

[seekermeister]

I checked the manual about memok, and below is a snip from the description. It may just be a failsafe device, that shouldn't be used for general compatibility, but it is more than just a pass/fail indicator.

 

[Solarstarshines]

I'm trying to decide which RAM or order, to go with a motherboard that I just ordered:

Asus M4A89GTD PRO/USB3 Socket AM3/ AMD 890GX New Board - eBay (item 190510537291 end time Jun-07-11 12:46:06 PDT)

I came across some Patriot RAM that is attractively priced:

Patriot Viper II PGV34G1600ELK 4096MB PC12800 DDR3 Dual Channel Memory Upgrade - 4GB (2 x 2048MB), 1600MHz at TigerDirect.com

But it looks a bit strange with it's notched top edge. I don't want to make the decision based only on looks, so I'm posting in order to get some insight into whether this is my best choice?

This will also be used with an AMD Phenom II X6 1090T processor, if that makes any difference in choosing...also the function where I expect that these decisions may matter most, is for video encoding.

I use ddr2 patriot viper ram and i must say it is worth every penny it is low latency and has good timmings on the winsat .....so you will be looking good

 

[Fumz]

I checked the manual about memok, and below is a snip from the description. It may just be a failsafe device, that shouldn't be used for general compatibility, but it is more than just a pass/fail indicator.

Ahh... learn something new everyday.

I would not rely on it. If a kit of RAM is incompatible with a board the only thing that resolvse the issue is a bios update. Yes, often you can get incompatible sticks to work, and this may... MAY be able to get a really out of whack stick to boot, but... it's a pretty safe bet that the RAM is going to run like crap relative to what it would run like timed by SPD or manually.

More importantly though, this tool would be ok it all it had to do was adjust timings, but I suspect (i don't know) it's also adjusting voltage. How much and which way would depend on the kit... and while the board may like the new settings it's applied, the memory may not... just something to consider.

 

[seekermeister]

I have a lot to learn about this motherboard. I just downloaded 18 pieces of software for it from Asus, and I don't know what half of them are for, but I guess that I will figure it out when I start putting it all together.

 

[GeneO]

I checked the manual about memok, and below is a snip from the description. It may just be a failsafe device, that shouldn't be used for general compatibility, but it is more than just a pass/fail indicator.

I believe you are correct about it being a failsafe device - it may end up operating your RAM at much less than the advertised performance and higher voltage than it should be just to get you to boot.

 

[seekermeister]

Still wavering on the decision. I noticed that many in the QVL are suffixed XMP, so I Googled and found that stand for a memory profile that was created by Intel. Does that mean that RAM with this designation is not a good choice for an AMD machine?

 

[Fumz]

No, it only means that it's also able to run well in an Intel rig at certain settings. If it's on the board's QVL, then it'll work well.

The level of "living dangerous" inside you is like... zero, isn't it? Buy a kit man! You're not going to do any better than what's on the QVL.

 

[seekermeister]

Fumz,

The level of "living dangerous" inside you is like... zero, isn't it?

I have lived dangerously for many years, in terms of computers. That was due to my own ignorance, rather than a devil-may-care attitude. I now much prefer to ask questions first, rather than questions mingled with flustration later. I agree that I need to make a decision, otherwise the motherboard and processor will arrive, and I won't even be able to test them, much less assemble them into a new build. What raised this question, is that I read elsewhere, that it was necessary to enable EMP in the BIOS of Intel boards, and I don't think that can be done with AMD boards. My interest in the EMP boards is that it seems that almost all of the lower CAS RAM (i.e. 7-7-7-20) is designated in this fashion. Yet, if EMP can't be enabled, I'm wondering if those CAS numbers would still be valid?

For some reason, it seems that almost all of the high performance RAM on the QVL has been discontinued. I did run across a set of used Mushkin which would cost ~$80 shipped, which is expensive for used RAM, yet from what I have seen of other Mushkin RAM, that really isn't unreasonable.

 

[Layback Bear]

Their are many rams that can be used with tricks. If one is not sure, doesn't want to take a chance, or doesn't have the knowledge to play with these rams just buy what the motherboard manufacture recommends and be done with it.