6GB RAM ( 2 + 4 ) in my system, it means no dual channel mode?

Hi, I would like to know whether my system will be running in single or dual channel mode? And, which one will benefits me more? More RAM size or more memory bandwidth? Please advice.

 

it will run in flex mode. it'll be like 4gb dual channel mode with 2 GB i reserve if needed.

 

Actually, it will run just fine in the dual channel mode. The PM55 chipset will use the "dual channel" mode with two SIMMs... regardless of their sizes. So, there's no need to have "matched pairs" of RAM chips to make the dual channel feature work.

 

I'd be interested in some evidence of this. I know the spec doesn't require identical DIMMs for dual channel to work, I've just never seen a system that actually supported it with different size modules. Not saying you aren't right, I'd just like to see some proof.

 

What type of evidence do you need? I have 4+2GB modules.

 

I just wanted documentation from Intel and/or proof that you're running in dual channel mode. Simply having them installed doesn't mean they're running dual channel.

Dual-channel architecture - Wikipedia, the free encyclopedia

 

As far as I know they will run in Flex Mode, like argyle pointed out.

 

Nope - Dual Channel.
Here you go.

 

What does CPU-Z report your memory as? Here's mine with 2 4GB DIMMs. Note that Channels # is "Dual".

 

We cross-posted. Good to know it actually works somewhere as the original spec suggested, thanks.

 

Nice, good news, I guess I'll be getting my 2nd R2 with 6GB of ram after all.

 

2nd R2? One is not enough? o()

 

My girlfriend is buying my current R2 from me, and I'm buying a new one in Lunar Silver with CF 5870's.

 

Hehe, nice one there. I'll probably upgrade slowly. A bit worried about the 5870's temps. 20% boost doesn't justify the 1/2 life span, IMHO.

 

I hope your girlfriend reads this post...

YOU SHOULD GIVE HER THE LAPTOP FREE. Hope I stirred up some trouble for ya there...lol. j/k.

 

What are you basing that assumption of half the lifespan on?

 

That is a strictly personal opinion based on a firm disbelief that any GPU can survive for too long with memory temps hitting 90C+ constantly while gaming. I've seen a few furmark test results with 5870 hitting 95+ (for example, my 4870's almost never leave 80C , I mean the MEM sensors, as the Core runs much cooler).
Anyway, I'll wait and see more tests and benches done before thinking of upgrading.

 

Brings back memories of the G92s on the M1730.

 

So 2GB + 4GB will work on Dual Channel on PM55 but will it also work on previous platform - PM45?

 

what does the bios report (Memory Channel Mode)? does it report dual channel too with the 4+2 config? I noticed the UK site offers 6GB dual channel but the aussie one omits the "dual" for the 6gb options.

 

Just checked - BIOS reports dual channel as well.

 

Cani upgrade to 16gb ram @ 1333mhz in M15x. 8GB each slot.

Possible not possible?

 

Are you doing this just for fun or something?

I'm not aware of anything that requires(or can even utilize) 16gb of ram haha.

 

No friend i'm just asking to know

 

If you could find 8GB notebook RAM modules, it should have no issues recognizing it. But as even 4GB modules are rare, its not really an issue just yet.

 

I love having 8 gb of ram and If I could I would get 16gb of ram and I would be loving it. . But I learn how to use the extra ram.

 

I believe that the PM55 chipset only supports up to 8GB of RAM.

 

Yah, it would be nice to have 4 slots and put the fast HyperX 4x2GB. Unfortunately, those don't come in 4GB sticks.

 

Not yet but I am pretty sure they will at some point.

 

Does anybody know if there´s a performance gain/hit with the 4+2 option?

My laptop came with 2+4 and I just swapped them for the heck of it...

 

Since it's been proven to run dual channel with 4+2, as long as you're not maxing the ram out, you'll see no difference going to 4+4 unless you buy ram with better timings, and even still your gains will likely hardly be noticeable.

 

True.
I wish we could benefit from this though

 

the memory controller in the i5 and i7 are on the die of the processor, the PM55 doesn't have anything to do with it. The only restriction preventing us(if it's even restricted) from using 8GB modules would be the bios. The M6500 uses 4GB modules in 4 slots to use 16GB of ram, and that laptop has the PM55 and i5/i7 processors just like we do.

we could if we could adjust memory timmings 1333mhz ram @ CAS7 anyone?

afaik, asynchronous(mixed sized modules) DCM is closer to single channel mode than it is the performance of real synchronous(matched sized modules) dual channel. So there should be some big bandwidth gains if you're benchmarking, otherwise I agree, not much of a difference.

 

According to Tom's Hardware

I think the only way we could really compare is by doing bench ourselves but even there it seems there is almost no difference in between the best RAM and the worst.

Full RAM comparison review

 

well, here's mine, 1333mhz cas 9 8GB

 

Actually the link I posted above can lead here - CAS7 @1333

 

the modules are SPD'd to work @ the JEDEC CAS which is 9 which means they'll default to work @ CAS 9 like all the other DDR1333 ram. Without a way to change the timings manualy we can't

 

Do you think that "programmable CAS latency : 5,7...10" is just another marketing BS?

 

Not sure if the memory architecture has changed on the newer platforms but:

4+2gb is asymmetrical dual channel (aka Intel flex mode)

4+4gb is symmetrical (true) dual channel

A 4gb single stick is single channel

If your running 4 + 2 gb sticks on flex mode, the common size on both sticks (2gb) will run dual channel while the rest is accessed as a single.

Theoretical RAM peak rates:

1333mhz DDR x 8bytes x (2) Dual channel = 21.3gb/s

1333mhz DDR x 8bytes x (1.5) Flex Channel = 15.9gb/s

1333mhz DDR x 8bytes x (1) Single Channel = 10.6gb/s

Even on single channel it wont bottleneck transfer rates to the CPU.

 

no no, I'm sure it can run at those speeds, I just don't see how we can change it in the M17x R2. There's no way to change the ram timings in our computers with the PM55, unless kingston is proving a software level SPD programming application with their ram, I doubt this however. You *might* be able to change it with Nvidia system tools in the R1, since I know that application allows Timing changes and it's using the nvidia chip set with the MCH on the NB instead of the processor, however I can't remember if it would actually change them in the R1.

afaik, the M17x does not support flex mode.

 

i have 4 gigs of ram at 1333.i would like to increase it to 8 i just call dell and they well help me.i never owened a gaming pc before.i would like 8 gig's of ram if it well speed up fps without having to overclock anything.i am a noob i dont knoww the first thing about overclocking but i am digesting every tid bit of info.right now i am using fraps it is between 30 and 50. jumping back and forth.i would like to get it to a steady 45 to 55 is that even possible??

 

You're just wasting money if you think upgrading to 8GB from 4GB will give you any sort of performance benefit in gaming. Bottom line: save your money and stick with 4GB.