TR Forums

7 years back i was introduced to Z Ram concept i read in some thread discussion at TR.

I always wanted to try it, but due to the ZRAM products high price in India, it remained in my wishlist.

I recently upgraded my system and was able to install 12GB RAM at a very low price.
5 days back while updating my Graphic card driver on AMD's support page, i came across AMD's ZRAM software.
I installed the free version of ZRAM software and set up 4 GB drive dedicated to Z RAM - moved Mozilla, Chrome, Winamp & VLC into that drive and WOW - this apps starts at blazing speed, feels absolute smooth while operating. (Not sure if it is because of Z RAM but my Peacekeeper score for chrome is 6200)

I don't have SSD, so i don't know what's its speed like, but i can still say with full confidence, SSD is no match against ZRAM.

I want to know usecases of ZRam that gerbils at TR might be using it for. Since i have a 4GB Zram, i can't install games in it, but can you suggest what else should i install in that drive, so that my daily PC usage is further improved ?

EDIT: For people who are not aware about ZRAM or RAM Drive - http://en.wikipedia.org/wiki/RAM_disk

Maybe move the PageFile to that area - Other than that, I guess any program that will benefit from fast random access read and write?

(I don't use it. I had to Google what Z RAM was, as I've never seen it mentioned anywhere before.)

geekl33tgamer wrote:

Maybe move the PageFile to that area - Other than that, I guess any program that will benefit from fast random access read and write?

(I don't use it. I had to Google what Z RAM was, as I've never seen it mentioned anywhere before.)

That sounds like a great idea - pagefile in ZRAM should make the overall system very fast. Thanks for the tip.

Jigar wrote:

That sounds like a great idea - pagefile in ZRAM should make the overall system very fast. Thanks for the tip.

Np. A few years ago when I was using a mechanical HDD and a small 64GB SSD together, I bumped Windows and the PageFile off to the SSD and left everything else on the platters.

Performance speedup was immediate and noticeable, and my motherboard is hampered by a lowly 3GB/Sec SATA interface to boot. You should be laughing...

I'm not sure what ZRam is in the context of this discussion, exactly. Is that what they're calling their RAMdisk software over there?

Pagefile on a RAMdisk defeats the purpose of a pagefile. Things are paged out to the pagefile when they're not needed, to relieve memory pressure. So you're basically just making the memory subsystem work harder than it does normally.

Savyg wrote:

I'm not sure what ZRam is in the context of this discussion, exactly. Is that what they're calling their RAMdisk software over there?

Pagefile on a RAMdisk defeats the purpose of a pagefile. Things are paged out to the pagefile when they're not needed, to relieve memory pressure. So you're basically just making the memory subsystem work harder than it does normally.

It can make sense if you're still running a 32-bit OS on a motherboard that can take more than 4GB of RAM. But that's becoming a less common use case as everyone migrates to 64-bit OSes.

Savyg wrote:

Things are paged out to the pagefile when they're not needed, to relieve memory pressure.

Exactly and we also know while accessing pagefile from HDD, PC does feel slow. if i fool the windows into paging it in the RAM itself i should see an overall system boost as my system sees 8 GB RAM anyway (Actually it is 12GB but 4 GB is ZRAM)

Savyg wrote:

So you're basically just making the memory subsystem work harder than it does normally.

Atleast its worth trying, let me get back to you after experimenting this idea for few days.

You can get the same results with less overhead by disabling the pagefile feature completely.

RAMdisks are used when you want faster access to data that is normally not stored in RAM.

In your case the data is being stored in RAM then moved onto a disk into a pagefile. Since the data is already available in RAM there is no need to use a RAMdisk. Rather, you need to tell your OS to Not move the data out of RAM and onto a drive.

Though I have never tried a ramdisk I have read that it is way faster then a SSD. I mean a SATA3 connection to the fastest SSD is only a bit over 500mbps. A RAMDISK on the other hand is going to give you at least 10-20 times that speed considering since Sandy Bridge memory bandwidth in dual channel mode is averaging around 20 GB a second. I figure a RAMDISK configuration will only use half that speed @ around 10gb a second since it is probably writing to only one channel of memory. But considering I do not actually know how they work exactly you might get dual channel speeds. So any Gerbil can feel free to correct me and tell me I do not know what I am talking about but I think I have the general idea correct but I am far from positive.

vargis14 wrote:

Though I have never tried a ramdisk I have read that it is way faster then a SSD. I mean a SATA3 connection to the fastest SSD is only a bit over 500mbps. A RAMDISK on the other hand is going to give you at least 10-20 times that speed considering since Sandy Bridge memory bandwidth in dual channel mode is averaging around 20 GB a second. I figure a RAMDISK configuration will only use half that speed @ around 10gb a second since it is probably writing to only one channel of memory. But considering I do not actually know how they work exactly you might get dual channel speeds. So any Gerbil can feel free to correct me and tell me I do not know what I am talking about but I think I have the general idea correct but I am far from positive.

Ram disk is Raw data power - i am quiet impressed by the performance. If my experiment goes well, i might purchase 32 GB RAM out of which 16GB would be ZRAM.

Just run a 64-bit OS and let the OS manage the RAM.

There are some edge case performance situations where Windows does a really terrible job with swapping, and so in those cases it can make sense. We have a Java compiler farm and we use StawWind's RamDisk product to eek out about 25-200% better performance.

I'm really confused... I thought Z-RAM was an abandoned hardware implementation. A quick Google search shows a linux zram module, and AMD's RAMdisk (which is just a re-brand of Dataram's software).

keltor wrote:

There are some edge case performance situations where Windows does a really terrible job with swapping, and so in those cases it can make sense. We have a Java compiler farm and we use StawWind's RamDisk product to eek out about 25-200% better performance.

Compilers should be capable of managing memory properly themselves I'd think, but yes there are edge cases where this would be useful.

The way he's talking about using it is harmful to the performance of all non paging apps, so I don't see the point.

just brew it! wrote:

Just run a 64-bit OS and let the OS manage the RAM.

Its just an experiment to see if this idea does anything good.

Savyg wrote:

keltor wrote:

There are some edge case performance situations where Windows does a really terrible job with swapping, and so in those cases it can make sense. We have a Java compiler farm and we use StawWind's RamDisk product to eek out about 25-200% better performance.

Compilers should be capable of managing memory properly themselves I'd think, but yes there are edge cases where this would be useful.

The way he's talking about using it is harmful to the performance of all non paging apps, so I don't see the point.

OK, i didn't touch the existing Pagefile which was 12GB system managed (Recommended was 18 by windows) but created 2.5 GB Pagefile in the Z RAM - Initially there was nothing significant but after 3 hours of normal gaming and usage. Below are my observation.

1) After system restart - it feels more responsive.
2) Overall system feels smooth - not all, but some applications are now starting fast.
3) Its too early to give the verdict, but it does feel like creating a bit of a pagefile in ZRAM does help the system.

I am not sure of disabling the pagefile which is on my HDD currently, but i will try it later, may be after a week of testing the current settings.