How hard 4 memory sticks really are on the controller?

[Rhezuss]

I often see comments about how hard on the memory controller 4 mem sticks can be...but how hard is it really?

I would like to upgrade to 16gb, adding another 2x4gb, but i'm hesitant after reading many comments about this.

I've ran many PCs (from SDRAM to DDR1 and 2) with 4 sticks and never had problems with this.

Recommended?

 

[Eeqmcsq]

I think the "strain" using 4 memory sticks is only a factor if you overclock or run at the highest speeds or the tightest timings or things like that. I've never had any problems with 4 sticks, such as 4x4GB DDR2-800 and 4x4GB DDR3-1333 using the stock speeds and timings.

 

[Cerb]

You'll just have to run them slower. No big deal. Also, set command rate to 2T, if it is an option.

My old P35, can run any 2 of my sticks (all same SKU) at >950MHz, but with 4, I can't get to 850MHz, even with substantial RAM and RAM controller overvolting.

One of my older Athlon XP boards could run 4 sticks of DDR, but only up to 133MHz.

With modern DDR3, you might get stuck with 1333MHz, or 1066MHz, depending on mobo. But, you'll have 16GB of RAM, which is far more important than of it runs at 1866MHz or whatever.

 

[Rhezuss]

Even if 1866 is the "stock speed" for those sticks?

Could I simply run them at 1600?

 

[Cerb]

Even if 1866 is the "stock speed" for those sticks?

That only applies for running a single stick per channel.

This is also the reason that server CPUs universally support slower RAM: their users are expected to fill up the slots more often.

Just set it to auto, and if it boots correctly, let it run a few memtest passes. If that works, leave it at whatever speed that is. Even if you have an AMD rig, that can benefit from faster RAM, having more RAM will be of greater benefit, if you can use it. If it won't boot on auto, try various manual settings.

 

[Rhezuss]

Ok so my second set...I should get the Ares DDR3-1600 instead of 1866 knowing i'll run them on Auto (which is 1600)?

EDIT: Well both are at the same price lol...

 

[Cerb]

If you can get the same SKU you have now, definitely do that. Regardless of speed you end up running at, when adding RAM, that will radically decrease the chances of having any compatibility issues.

Without using an AMD APU, worrying about the memory speeds is wasted time and effort. Even in cases where it can matter, you're likely to be dealing with a <10% throughput loss, while benefiting from far less SSD/HDD access (though, for most programs, it's more like 0.1-0.5%). If you use Adobe content creation programs, you may very well get gains from more RAM directly, rather than simply reduced disk I/O, as well.

 

[nenforcer]

4 identical sticks usually works just fine, its why there are 4 slots to begin with its not just for show, although typically at reduced settings because of the higher electrical load.

It when you start mixing and matching different SKU's and voltages when things go haywire.

 

[Sohaltang]

Im running 4gb1.65v corsair 7-8-7-20 and 8 gb g.Skill 9-9-9-24 1.5v @ 1800oc mhz 1.6v and 9-8-9-22. Ivery Bridge and so far no problems. Might blow up tomm. F it.

 

[jaqie]

I have a phenom II thuban x6 (which is designed only for ddr3-1333) running four sticks of kingston hyperx 9-9-9-24 4gb 1600 1.65v at 9-9-9-24 1600 1.5v and it is entirely prime stable and has been for two years, the motherboard is a ga-990fxa-ud3 and the power supply is a pre ocz pc power & cooling silencer 420w. I have had issues with 4 sticks of ram in the old socket 939 x2 days (ddr400 low latency was iffy) but never a single issue since then... I always run the ram at what it is rated at, though sometimes lower voltage, and always run 4 sticks, and I have never since that x2 socket 939 with ddr1 had issue. Overclocking ram is not in my vocabulary and never has been, the strain people are talking about must honestly have either to do with crap power supplies crap motherboards or crap (or overclocked) ram.... or maybe crap motherboards with bad pcb trace designing... which is why I always buy good gigabyte stuff.

 

[Cerb]

You had issues back then. Well, you could still, today. It's a fundamental issue with unbuffered SDRAM, no matter your motherboard or power supply (though motherboard RAM traces probably have as much to do with it as the RAM itself, and everything else, including PSU, probably doesn't matter, as long as it's not a Powmax or other POS). You might not (all mine works at rated speed, and just won't overclock, FI), but it is fine if it needs to be slowed down a bit. On an SB or IB CPU, 4 banks/channel of 1333 or greater should be able to run at 1333. If stock speed is 1866, but it's only stable to 1333, it is not a malfunction (it also won't affect performance enough to notice, outside of cherry-picked benchmarks).

 

[rgallant]

The decision to implement T-Branch was made because most people are now running 4 DIMMs (prices are very reasonable). It provides a little more system overhead, by reducing slot to slot skew. Any skew has to be countered in the IMC read/write schedule and eventually eats into margin. So yes for 4 DIMMs only, and also yes that its for the guys that like to push. The reason Intel was said to be impressed is because ASUS had to model the transmission line impedances and layout themselves - something most vendors won't and do not do. Most boards use the Intel generic layout and transmission line impedances so there is some truth behind the part that Intel were glad we pushed the envelope of their design.

-Raja

Edit: one thing I should add that may be of benefit to those pushing 4 DIMMs, you should find that T-Branch may allow lower operating voltages for the memory bus (VDD) against conventional topologies. Any variance in skew between DQ and DQS lines due to daisy chaining of the single ended DQ lines, will have to be countered by fiddling with VDD to maintain a slew rate that keeps the DQ signal well centred with the DQS.
No matter what Sin says, we put a huge amount of work into this. We did not use Intel's stock layout and modelled the layout to ensure that we extended the 4 DIMM OC margins of the platform. All Z77 boards get T-Branch while the ROG boards are optimized further still. We don't just change VRMs on boards and leave it at that. Like all vendors we do have time constraints to work to, but we do have resources at our disposal that allow us to cram more of this kind of work into our designs.

http://www.overclock.net/t/1241807/asus-t-topology

at the high end 2 sticks better than 4 imo.

 

[tweakboy]

Raise DDR voltage a little in the bios. THen loosten timings. To what your inital RAM was... gl should work as a charm.