[2500cc]

What is theoretically possible with 64 bit CPU is still in 10^18 realm.
Because, other components/controllers are limited by the manufacturers.

What is available today is a different story.

The addressable memory available in any system is lowest of
. Adress width. For 64 bit systems it is 2^64
. Hardware limit set by the CPU manufacturer
. Software limit set by OS

For windows system on Intel 64 bit CPU, the limit set by Microsoft is 8Tb
Memory Limits for Windows Releases (Windows)
but the limits are much lower for other windows versions, with lower limit at around 4GB for home editions.
Obviously if you install 32-bit OS on a 64-bit architecture, the OS cannot make use of the capability the 64-bit offers. Because the 32-bit OS doesn't have the 64-bit architecture instruction set built in its kernel.

Also the 32-bit, application cannot make use of the 64-bit address space yet when installed on the 64-bit machine (H/w+OS)

But that does not mean that other Hardware/Software combinations are limited to the 8TB.
By Default it is limited, we are not talking about any tweaks here, just a default 64-bit arch.

There are tweaks like /PTE (for 32-bit OS) which when added to the boot.ini, the system increases the memory page size, there by increasing the ability of the OS to address more RAM.


In fact many scientific systems can be configured to adress and use much more RAM.
This is true, this can be done increasing the memory page size (by default 4KB)

That said, most of the systems have much lower maximum capacity for physical RAM. For example

. My system with dual Xeon has 192 GB on 16 RAM Slots.
. IBM Power 7 has 512 GB IBM Power 750 Express server specifications
. A home PC will max out at 16GB with 2 or 4 slots.

This limitation is due to the fact that the other hardware is not capable of supporting 8TB RAM. Though the CPU is capable of addressing the 8TB address spaces, there are other components (Memory Channels, DMA controller, etc) which are not sync yet.

By the way, are we talking about the RAM or Virtual memory ? The 8TB in question of this discussion is Virtual memory, not the RAM

Here is an examplef a supercomputer with 80TB RAM Memory Interface in Supercomputers | Professor Memory

PS: The 8TB am mentioning here is the limit of the process address space (Maximum Address space available to the process of 64-bit)

[akas_chauhan]

Theoretically 64 bit can support 2^64, but is it a reality NO.
Why, because there is no demand for such a huge address space as of now. Hence implementing such huge virtual addresses would increase the complexity and cost of address translation with not much benefit.

But
Windows is Supporting upto 16TB with AMD.
Linux supports upto 256TB as of today.

[wanderlust]

I recently received an upgraded lightweight notebook computer from my office with a solid state hard disk. Wow, what speed and what battery life! Beautiful, I am loving it. Battery life over 8 hour on full charge, weights around 1kg, boots up in less than half the time required by my older Lenovo.

[Thad E Ginathom]

Originally Posted by akas_chauhan

Linux supports up to 256TB as of today.

My system has 4Gb of physical ram, and never swaps, not even when I run virtual machines with nearly half of that memory assigned to them.

Of course, I am not doing anything like running scientific calculation software --- or running Windows software!

But still, better that limits should be high. 640k was not that long ago!

[anky]

Amd x2 240 2gb hynix ddr2 667 integrated ati radeon 3000 pci e grapgics with onboard lan and sound .Marvel ukon for lan I think . Have bought this cheap much cheaper than intel . Biostar board with dvi and benq 22" with 1680*1050 res. Can my daughters samsung n148 net book have 2gb or 4 gb ddr2 ram it comes with 1gb as std and is quite slow .Intel atom n450.

[MuzzledMoose]

My new config
i2500K on antec kuhler water cooling block running @4500MHZ
Cooler master HAF932 cabinet
8GB gskill ripjaws ram
Asus Z68 motherboard
Trusty old creative sound card with I/O drive
Asus GTX560ti X 2 on SLI
Antec 1000W PSU
23" LG 3D monitor
Razer Keyboard and mouse

[devarshi84]

Just added 4gigs extra to my Lamborghini. OS upgrade to 64-bit in process atm.

[cruiser@0523]

Planing to upgrade ram now, system gets slow when i open huge photoshop files (700mb-1GB) , planning on 2x corsair 8gb @ 1600mhz.

[Aroy]

Originally Posted by cruiser@0523

Planing to upgrade ram now, system gets slow when i open huge photoshop files (700mb-1GB) , planning on 2x corsair 8gb @ 1600mhz.

To utilise the RAM, you will need both 64 bit OS, as well as 64 bit Photoshop.

Also check the support by the Motherboard
. Maximum RAM chip size
. Type - DDR2, DDR3 etc
. Maximum total RAM

Please read up the technical manual of Photoshop, as in most cases you will get 2-4X speed up if you use an SSD as a scratch disk.

John Nack on Adobe : How to set up a great Photoshop machine

Optimize performance | Photoshop CS4, CS5

[cruiser@0523]

Originally Posted by Aroy

To utilise the RAM, you will need both 64 bit OS, as well as 64 bit Photoshop.

Also check the support by the Motherboard
. Maximum RAM chip size
. Type - DDR2, DDR3 etc
. Maximum total RAM

Please read up the technical manual of Photoshop, as in most cases you will get 2-4X speed up if you use an SSD as a scratch disk.

John Nack on Adobe : How to set up a great Photoshop machine

Optimize performance | Photoshop CS4, CS5

I have both running 64 bit, thanks for the links, i'll read up.

[PatienceWins]

I have a couple of DDR RAMs (only DDR, used to upgrade my old computer). 1 GB and 512 MB, I had to pay around 2.5k for the 1 GB RAM, which is unused as i got a new computer soon. Can anyone let me know how I can sell them (S.P road in Bangalore or any online classifieds)?

[JMaruru]

Originally Posted by PatienceWins

I have a couple of DDR RAMs (only DDR, used to upgrade my old computer). 1 GB and 512 MB, I had to pay around 2.5k for the 1 GB RAM, which is unused as i got a new computer soon. Can anyone let me know how I can sell them (S.P road in Bangalore or any online classifieds)?

It is better through online classifieds. You would get peanuts in SP Road.

[chevelle]

I have a dell precision 490. Was wondering if its a good idea to overclock it.

I installed systool, but it doesn't execute. it gives an error and doesn't start. I also tried putting fsb to 185 through command line, but still the same thing.

any pointers as to how i can overclock it

thanks

[Thad E Ginathom]

I installed a Silverstone SST-AP121 fan at the front of my P183 case, to pull in air and blow it over my 1tb disk, which is often the hottest thing in the system. It is doing a good job of reducing the entire system temperatures, and making almost no noise at a pwm-controlled 1000-ish RPM. I have been able to set the two stock antec tri-cool fans to low-speed. The total noise is reduced --- and it wasn't much before . I want to further control the fan speeds, but a first investigation into the Ubuntu pwmconfig and fancontrol programs has left me baffled. Probably best to leave it to the BIOS.

Also treated myself to some portable storage. A USB3.0 1Tb Toshiba Canvio is my new toy, while a Seagate Goflex USB2.0 is going to be my off-site backup device.

I'll keep it at another house, and bring it back every two or three weeks to update. It isn't a backup plan that would satisfy a commercial security audit, but it is a great deal better than an external drive three feet away from the machine, which is subject to almost all the same physical risks as the internal disks. Now I'm waiting on the discipline upgrade.

[Rehaan]

My little build has begun!! (Ignore the 2GB stick..lol)



I'm amazed at how cheap RAM is these days!! 16GB of 1600Mhz DDR3 was $117!

cya
R