Sign in with
Sign up | Sign in
Your question
Solved

RAM Upgrades

Last response: in Components
Share
June 2, 2012 7:06:56 PM

Hi all,
I'm keen learner of building computers. I want to know that memory specification of LGA 1155 socket CPU says Max RAM support of 32GB and max bandwidth Support of 21.2GB/s.

Considering the bandwidth support i can only install 2x8GB 1333Mhz RAM. And now even if i install more of it. CPU won't Use it right?

More about : ram upgrades

June 2, 2012 9:27:13 PM

There is no benefit for more than 8GB of memory for 99% of all users. Unless you're doing serious video editing/rendering, you only need 8GB. Also, DDR3-1600 is the "sweet spot" for price/performance, with good 8GB kits going for around $50. Faster memory helps very little outside specific tasks, while costing much more.
m
0
l
Related resources
June 3, 2012 2:41:02 AM

Rollu59. I got these figures from intel's official website.
http://ark.intel.com/products/52209 .

Willard i am into 3D softwares and HD video editing. Although i know that 8 GB is very much sufficient and 16GB is a luxury. But I want to understand the reason of mismatch Maximum memory capacity of a processor and it's max. memory bandwidth.
m
0
l
June 3, 2012 2:50:01 AM

You're confusing yourself. Sandy Bridge doesn't officially support 1600 RAM, meaning it doesn't officially support more bandwidth than 21 GB/s, but that doesn't mean it CAN'T do it.
m
0
l
June 3, 2012 3:05:26 AM

What I was asking 2 x 8 GB 1333ram maxing out the bandwidth! Like I said in my first reply the bandwidth is a function of the speed of the ram but does not limit the size.
Lets say you have 32 GB to send through the ram if you only have 16GB available and your bandwidth is 16GB/s you will fill the ram in 1 sec and the rest has to go to your page file on the HDD which is really slow. If you have on the other hand 32 GB available it will take 2 sec to fill the ram, which in that case will be much faster than running out of ram.
Basically the bandwidth does not limit the size of the ram rather tells you what time it does take for the ram to work processes.
m
0
l
June 3, 2012 3:30:08 AM

Djdecibel i know it doesn't supports 1600Mhz RAM. Willard said so :) .

Rolli59: as far as i know 2 sticks of 8GB MHz equals 21.2 Of bandwidth. Now if i have 32GB of data to be sent through RAM than i'll have to reduce my RAM MHz and install 32GB of RAM or use lesser amount of RAM coz remaining amount of RAM won't be used by CPU. Right?
m
0
l
June 3, 2012 3:38:59 AM

I admit that this gets slightly out of my realm of knowledge, but the bandwidth limit isn't a hard cap, is it? The limit is just the highest supported, not the absolute highest the IMC can use, right? Someone feel free to correct me, but there are people using 32 GB of 1600 RAM in a SB system, and I haven't ever seen anyone say that they had to reduce the RAM speed to make it work.
m
0
l
June 3, 2012 3:44:16 AM

mailhull said:
Now if i have 32GB of data to be sent through RAM than i'll have to reduce my RAM MHz and install 32GB of RAM or use lesser amount of RAM coz remaining amount of RAM won't be used by CPU. Right?

The amount of installed RAM is technically independent of how fast the memory can be run at.

If you have 2x8GB 1333MHz DIMMs and add two more 8GB 1333MHz DIMMs, you should be able to run the whole 32GB at 1333MHz unless flaws or interoperability problems cause this configuration to become unstable. Same goes for 1600MHz or higher.

What determines how fast the memory can run is the quality of the DIMM/chips, motherboard routing, CPU memory controller and how cleanly those components interact with each other, not the amount of RAM. With everything working properly, bandwidth will remain the same regardless of how much RAM you put in.
m
0
l
June 3, 2012 3:46:39 AM

mailhull said:
Djdecibel i know it doesn't supports 1600Mhz RAM. Willard said so :) .

Rolli59: as far as i know 2 sticks of 8GB MHz equals 21.2 Of bandwidth. Now if i have 32GB of data to be sent through RAM than i'll have to reduce my RAM MHz and install 32GB of RAM or use lesser amount of RAM coz remaining amount of RAM won't be used by CPU. Right?

It will use all the supported ram, bandwidth is a measurement quantity (GB) over / time (seconds) = GB/s basically is transfer speed, has absolutely nothing to do with limiting the size of it.
Look at this way you have to travel 100miles at 50MPH it takes you 2 hours but at 100mph its takes you 1hour but either way of travel gets you there in the end.
m
0
l
June 3, 2012 3:47:18 AM

Well as i know Bandwidth = Real clock Rate x 8. means for 1333Mhz bandwidth is 10664 ideally or a little lesser Practically. I think that even if people use 32GB of 1600 RAM in SB the CPU won't be using a complete of RAM and i feel probably lot of money is being wasted on extra RAM.
m
0
l
June 3, 2012 4:01:58 AM

OK, the main question I need answered here, for my own knowledge, would be, is the stated 21 GB/s bandwidth limit a hard limit, meaning the IMC will NEVER be able to handle more than that? If that's true, this argument makes a LOT more sense. If not, it makes NO sense. I don't think it is, but I need someone with more knowledge than I have about the situation to confirm it.
m
0
l
June 3, 2012 4:12:45 AM

Bandwidth is a speed measurement GB/seconds! When exceeded it just takes more time! The CPU loads information in the ram at its max speed (Bandwidth) until the ram is full (theoretically if you have big enough data package) what ever size is installed!
m
0
l
June 3, 2012 4:14:45 AM

rolli59 said:
Bandwidth is a speed measurement GB/seconds! When exceeded it just takes more time! The CPU loads information in the ram at its max speed (Bandwidth) until the ram is full (theoretically if you have big enough data package) what ever size is installed!


I get that, but is the stated limit really the limit (meaning it can't be exceeded, ever)?
m
0
l

Best solution

June 3, 2012 4:20:22 AM

DJDeCiBeL said:
OK, the main question I need answered here, for my own knowledge, would be, is the stated 21 GB/s bandwidth limit a hard limit, meaning the IMC will NEVER be able to handle more than that?

It will never OFFICIALLY handle more than that and never will on fully-locked chips like the i3.

However, on unlocked K-chips (2nnnK and 3nnnK), people can overclock the memory and core however far beyond OFFICIAL numbers they can reliably push them to at their own risk, which is how people are pushing Sandy Bridge to 2133MHz memory clock (~34GB/s) and 4.5+GHz core clock. Neither OFFICIALLY supported (there is no official standard for DDR3 beyond 1600MHz) but made available to enthusiasts for trial-and-error experimenting by unlocked multipliers. If it works, congrats. If it doesn't, better luck next time.

With K-chips and CPU+MoBo+RAM that are stable at 2133MHz, Sandy Bridge which is only officially specified for 21GB/s, overclocking can bump it to an officially UNsupported 34+Gbps.
Share
June 3, 2012 4:22:38 AM

InvalidError said:
It will never OFFICIALLY handle more than that and never will on fully-locked chips like the i3.

However, on unlocked K-chips (2nnnK and 3nnnK), people can overclock the memory and core however far beyond OFFICIAL numbers they can reliably push them to at their own risk, which is how people are pushing Sandy Bridge to 2133MHz memory clock (~34GB/s) and 4.5+GHz core clock. Neither OFFICIALLY supported (there is no official standard for DDR3 beyond 1600MHz) but made available to enthusiasts for trial-and-error experimenting by unlocked multipliers. If it works, congrats. If it doesn't, better luck next time.

With K-chips and CPU+MoBo+RAM that are stable at 2133MHz, Sandy Bridge which is only officially specified for 21GB/s, overclocking can bump it to an officially UNsupported 34+Gbps.


Thank you very much! That's exactly what I was looking for! :)  I always knew that it wasn't officially supported, but I always thought it could do more (the K series chips) and I was right on that.
m
0
l
June 3, 2012 4:28:35 AM

DJDeCiBeL said:
I get that, but is the stated limit really the limit (meaning it can't be exceeded, ever)?

It is calculated on the fastest supported ram times two channels not modules! As seen in the table in this article http://en.wikipedia.org/wiki/DDR3_SDRAM
It will change with faster ram.
m
0
l
June 3, 2012 4:30:29 AM

I think i got my answers. To conclude it means that you can install more RAM when you indulge in overclocking activities otherwise OFFICIALLY SB supports as i was writing. Right?

Also Djdecibel: this means 32GB of 1600 on Sandy Bridge was sort of waste untill Overclocking comes in to play.
m
0
l
June 3, 2012 4:30:33 AM

rolli59 said:
It is calculated on the fastest supported ram times two channels not modules! As seen in the table in this article http://en.wikipedia.org/wiki/DDR3_SDRAM
It will change with faster ram.


Yeah, InvalidError explained exactly what I wanted to know. I'm set now, just wanted to get that straight for my own future knowledge.
m
0
l
June 3, 2012 4:33:18 AM

mailhull said:
Also Djdecibel: this means 32GB of 1600 on Sandy Bridge was sort of waste untill Overclocking comes in to play.


1600 RAM isn't really needed anyway (even though I have 1600 RAM myself), but 32GB of RAM is a waste for most people (99.9%), regardless. I was just trying to get things cleared up in my own mind and set myself straight.
m
0
l
June 3, 2012 4:34:55 AM

Sure. It was worth a discussion. Thanks all. Cleared many things and saved lot of future money :D 
m
0
l
June 3, 2012 4:44:17 AM

mailhull said:
I think i got my answers. To conclude it means that you can install more RAM when you indulge in overclocking activities otherwise OFFICIALLY SB supports as i was writing. Right?

Also Djdecibel: this means 32GB of 1600 on Sandy Bridge was sort of waste untill Overclocking comes in to play.

You got this completely WRONG.

How much RAM is worth having depends entirely on how much RAM your applications typically end up using, it has absolutely nothing to do with overclocking, other than the fact that overclocking a memory bus with more DIMMs on it tends to increase the risk of running into stability problems so you want the fewest DIMMs possible per channel for overclocking.

The amount of RAM installed and bandwidth have absolutely no direct relation to each other. High memory bandwidth is worth having for applications that benefit from high memory bandwidth even if the application itself only needs 1GB RAM. Large amounts of memory are worth having for applications that require tons of RAM to hold periodically used data or cache interim computation results instead of having to save/reload/recompute it from disk or original data all the time.

The amount of RAM and the amount of bandwidth have completely different purposes and implications.
m
0
l
June 3, 2012 11:06:43 AM

Thanks for intense explanation. It was really helping. cheers!
m
0
l
June 13, 2012 3:28:22 AM

Best answer selected by mailhull.
m
0
l
!