Core i7 Games and Memory Testing 6GB vs 3GB

[XMSYellowbeard]

Back in April 2008 we tested 4GB vs 2GB. Now that the Core i7 memory offerings are different, we did more testing with 6GB vs 3GB. We got very similar results. Vista with 3GB on i7 is good but 6GB is much better.

Application Note 811: http://www.corsairmemory.com/appnotes/default.aspx

 

[Maziar]

Thanks for the link
Hooray 5000th post

 

[gamerk316]

In short: Vista requires twice as much RAM as any other OS to run just as well

 

[rodney_ws]

Anyone looking at an i7 shouldn't be looking at anything less than 6GB. With all of the costs associated with i7, it just doesn't make any sense to settle for 3GB. If you can only afford 3GB, you should save your pennies or just get a Penryn.

 

[geofelt]

In short: Vista requires twice as much RAM as any other OS to run just as well

Not exactly.
Vista uses the available ram to avoid I/O to the hard drive such as paging and application loading.

 

[powerbaselx]

Back in April 2008 we tested 4GB vs 2GB. Now that the Core i7 memory offerings are different, we did more testing with 6GB vs 3GB. We got very similar results. Vista with 3GB on i7 is good but 6GB is much better.

Application Note 811: http://www.corsairmemory.com/appnotes/default.aspx

This test refers to Vista 64bits... most people have XP or Vista 32bits and so 3GB is enough for the reasons we all know.
I have no doubt a 64bits OS takes much more advantage of 6GB or even 12GB or 18GB memory but the thing is that while people keep playing on 32bits 3GB memory is enough.

 

[Scotteq]

This test refers to Vista 64bits... most people have XP or Vista 32bits and so 3GB is enough for the reasons we all know.
I have no doubt a 64bits OS takes much more advantage of 6GB or even 12GB or 18GB memory but the thing is that while people keep playing on 32bits 3GB memory is enough.

Actually, the test uses a 64 bit operating system because 32 bit ones only have 4GB worth of total address space (which needs include system resources other than RAM - such as memory mapped I/O for graphics). If they had used an x86 version of Windows, there would be no basis for comparison at all because the operating system cannot handle the extra RAM at all.

If it needs to be explained a different way: Think of address space like a 4 liter bucket: When you fill it with 1 liter (GB) for the system plus 3 more for RAM, the bucket is now completely full. It is not possible to add more to the same space. It simply will not fit.

This is why a 64 bit OS is used - the limit there is currently manually set to 128GB of address space, though theroetically it could handle several Exabytes worth.

 

[powerbaselx]

Actually, the test uses a 64 bit operating system because 32 bit ones only have 4GB worth of total address space (which needs include system resources other than RAM - such as memory mapped I/O for graphics). If they had used an x86 version of Windows, there would be no basis for comparison at all because the operating system cannot handle the extra RAM at all.

Ok but it should been mentioned that only these results only apply to 64bit OS to avoid misunderstooding and false expectations.
I understood also the commercial view of the memory vendor that conduct this test.

If it needs to be explained a different way: Think of address space like a 4 liter bucket: When you fill it with 1 liter (GB) for the system plus 3 more for RAM, the bucket is now completely full. It is not possible to add more to the same space. It simply will not fit.

Yes, but you imagine also an address space of a 6 liters bucket where you know that 90% of users cannot use more than 3 liters to 4 liters but you need to sell the whole 6 liters since you have now triple channel which, with current products, you need expensive 3 liters or you could buy more expensive 6 liters even it's not needed...

What i didn't understand so far is that people can play most of popular games on 64bit OS (XP or Vista) to take advantage of more memory.

 

[Scotteq]

In 32 bit Windows operating systems, the total addressable space available is 4GB. If you install a total of 4GB+ worth of RAM, the system will detect/use/display less than 4GB of total memory because of address space allocation for other critical functions, such as:

- System BIOS (including motherboard, add-on cards, etc..)
- Motherboards resources
- Memory mapped I/O
- Configuration for AGP/PCI-Ex/PCI
- Other memory allocations for PCI devices

Different onboard devices and different add-on cards (devices) will result of different total memory size. e.g. more PCI cards installed will require more memory resources, resulting of less memory free for other uses.

This limitation applies to most chipsets & Windows XP/Vista 32-bit version operating systems. Again, this is a limitation of the Operating System not having enough address space to allocate to the system *and* the RAM. Not allocating address space to devices renders them inoperable. Not allocating addresses to RAM simply results in the unaddressed section not being used in an otherwise fully functional computer. Therefore the OS designers assign RAM last.



The point I was making is that 4GB limit is a very real technical limitation, and applies to more than just RAM. So if you want to test the effects of large amounts of memory, then you are forced to use a 64 bit OS. Coming back with a 6GB example W/R/T a 32 bit OS is simply asinine because the operating system can not do that.

What i didn't understand so far is that people can play most of popular games on 64bit OS (XP or Vista) to take advantage of more memory.

The answer is very simple: It's because a 32 bit one can not provide the address space needed to run that much memory. So we/they use a 64 bit one.

 

[XMSYellowbeard]

Ok but it should been mentioned that only these results only apply to 64bit OS to avoid misunderstooding and false expectations.

The previous testing in AN804 goes into this limitation in great detail. AN804 is linked in the first paragraph of this paper. We did not see the need to be redundant with several pages of information we had already provided.

 

[powerbaselx]

The previous testing in AN804 goes into this limitation in great detail. AN804 is linked in the first paragraph of this paper. We did not see the need to be redundant with several pages of information we had already provided.

I'm not questioning those tests or others. I'm glad you wrote the reports so people can buy with a little more information.
What i'm saying is that the thread title should have mentioned that the test were conducted only on 64bit platform. The first time i read it i thought it included also 32bit which called my attention since 6GB RAM aren't really more useful than 3GB or 4GB if i don't plan to go to XP or Vista or Windows7 64bit in the next couple of years (which, let's be honest, the mass market probably won't...).

 

[powerbaselx]

In 32 bit Windows operating systems, the total addressable space available is 4GB. (...)

We agree from the beggining with this. That's not the point of this conversation.

What i didn't understand so far is that people can play most of popular games on 64bit OS (XP or Vista) to take advantage of more memory.

Sorry. I wrote the sentence wrong which lead to confusion... it should have been:
"What i didn't understand so far is that <b>IF</b> people can play most of popular games on 64bit OS (XP or Vista) to take advantage of more memory."

What i needed to know, and it is very important, is that if people can play the Top Games like Crysis or Supreme Commander or Far Cry 4, etc, on 64bit OS. I believe these games are compiled on 32bit OS and may have trouble running on 64bit Windows, no?

Thanks for your patience!

 

[Scotteq]

Sorry. I wrote the sentence wrong which lead to confusion... it should have been:
"What i didn't understand so far is that <b>IF</b> people can play most of popular games on 64bit OS (XP or Vista) to take advantage of more memory."

What i needed to know, and it is very important, is that if people can play the Top Games like Crysis or Supreme Commander or Far Cry 4, etc, on 64bit OS. I believe these games are compiled on 32bit OS and may have trouble running on 64bit Windows, no?

The answer to the gaming question is "Yes, You can play Crysis, Supreme Commander, Far Cry, CoH, or whatever game you choose on 64 bit Windows with NO CHANGES"'


- - Well Scott... How is that possible??


Thank AMD: They wrote the current X64 (F/K/A X86-64) specification with the express purpose that the instruction set is fully backwards compatible. This means the 64 bit processor (you already have!!!) in your computer can and will run the binaries with no changes at all.

Intel created their "Itanium" series of processors as their 64 bit offering. From an industry standpoint IA-64 was a big problem because none of the instructions are/were backwards compatible. So you had to create/compile specifically for this processor if you wanted to run anything. This effort was rewarded with a niche, but the bottom line is that *nobody* wants to rewrite and/or recompile all their software.

So the AMD created standard won the battle. Intel recognized this, licenced it, and called it 'X64'.



- - OK Scott, but that only addresses the Hardware level...


Yup!

Now - We've already touched on instructions to/from the processor. On the software to OS side the rough equivalent is an "API" (Administrative Programming Interface). These are the instructions a programmer uses to write code for a given piece of software. In this case, the APIs are for Windows. And guess what? Given the same version, a Windows API call is a windows API call is a windows API call.


- - AAAAHAA!! Stop Right There!!! If they're the same, they why the stink with drivers and support?


Two things: The first is that Microsoft changed the Driver model between XP and Vista - The API's changed. So now you have to have a driver written one way for XP, and another written differently for Vista. Some vendors handled it, others were less good... The other thing that changed is Vista does not allow Drivers to run inside protected space (read "talk Directly to the core of the OS"), because of Security related complaints/issues that Microsoft routinely get raked over the coals for. Some makers presumed that wasn't the case, or failed to properly account for the change. You would think this shouldn't be that big a deal, but it was common to use shortcuts... which became disallowed under the new layout.

But drivers aren't full programs and aren't handled the same way.




So, as a Programmer, you write code to a Windows API, and compile for your X64 Processor. Done deal - and your code runs on both. For a Hardware vendor, you have to have several sets of drivers (XP32 and 64, plus Vista 32 and 64). And for a consumer, make sure you check the label on the box for the OS version you are using and install the correct drivers.




***For those who are more technical than I - YES, I fully understand I have oversimplified things for the sake of clarity.

 

[powerbaselx]

The answer to the gaming question is "Yes, You can play Crysis, Supreme Commander, Far Cry, CoH, or whatever game you choose on 64 bit Windows with NO CHANGES"'

- - Well Scott... thank you very much for your looooooooooooooong explanation, but you didn't have to enter in history details and the battles between Intel and AMD to answer it simple!

***For those who are more technical than I - YES, I fully understand I have oversimplified things for the sake of clarity.

LOL!

yeah, yeah, yeah. You're the best! Thanks for your help... that's also what these forums are for...

 

[Blur]

Thx for info