Thinkpads Forum

dhinged wrote:
Any other workarounds or hacks or whatever would be nice to know.

For the umpteenth time: there are NONE...

You can check RAM speed via CPU-Z.
If you installed faster speed ram it'll downclock to 667 for compatability reasons.

ajkula66 wrote:

dhinged wrote:
Any other workarounds or hacks or whatever would be nice to know.

For the umpteenth time: there are NONE...

OK, then Intel is lying by saying their chip can use 4GB of memory with a 32-bit controller.

dhinged wrote: OK, then Intel is lying by saying their chip can use 4GB of memory with a 32-bit controller.

It would not be the first information on their website that doesn't hold water in real life.

You've tried here.

You've tried on Lenovo Forum.

Will it really take for David Hill to tell you that a ThinkPad from this era can NOT utilize more than 3GB of RAM?

Given that Intel had wanted to uses codes to unlock a Pentium processor in September of 2010, I wouldn't doubt they limited the chipset.
Besides, even if you can unlock it the chipset somehow, 4GB ram sticks are very pricey.

Just think of it like a car, you got the full horsepower at the crank, but the transmission loses about 13% when the power goes to the wheels.

ajkula66 wrote:

dhinged wrote: OK, then Intel is lying by saying their chip can use 4GB of memory with a 32-bit controller.

It would not be the first information on their website that doesn't hold water in real life.

You've tried here.

You've tried on Lenovo Forum.

Will it really take for David Hill to tell you that a ThinkPad from this era can NOT utilize more than 3GB of RAM?

It's not about being told whether it will or won't, it's about knowing why and if there's a way around it. However I found an article that better explains it for me and I will post that.

dhinged wrote:
It's not about being told whether it will or won't, it's about knowing why and if there's a way around it.

Well, the fact that there is NO workaround the given chipset limitation has been explained - in a plethora of manners - by some of the most knowledgeable forum members and I'm not talking about myself. That's why I brought up David Hill.

However I found an article that better explains it for me and I will post that.

Whatever works for you as long as we stop beating this dead horse that has been turned into sausages, eaten, digested and disposed of years ago...

I found an article link on the Lenovo forum that better explains why this is not possible:

http://www.cnet.com/news/macbook-pro-co ... -3-gb-ram/

It is the 945 chipset, and the keyword that hit the nail for me was "virtual", in that "the virtual space between 3.5 GB of RAM and 3.75 GB of RAM is occupied by PCI Express data" and by virtual I'm assuming "on the hard disk when only 3GB of RAM is installed", so I'm assuming when 4GB is installed, it's actually using that area on the RAM... but maybe it's still using the hard drive, and that's what I'm not sure of in the article. My point of confusion was not being sure whether that extra GB was actually being utilized by anything.

So my question now is: is there actually any benefit to having 4GB installed, ie, will that extra GB actually be used in the RAM or is it still only being allocated in hard disk virtual space? (if the latter, my sneaky question is can it be reassigned to take advantage of the unused GB on the RAM stick instead?!) The former of course would speed things up as it wouldn't have to use hard disk space for these "virtual" allocations.

It also of course seems dishonest for Intel and HP to report that it can use 4GB if nothing ever actually does since people bought that much instead of just 3GB (like me).

Please forgive me while I learn the guts of memory handling as that is one feature I have not studied in-depth.

dhinged wrote:
So my question now is: is there actually any benefit to having 4GB installed,

No.

dhinged wrote:Please forgive me while I learn the guts of memory handling as that is one feature I have not studied in-depth.

Nothing to forgive. We are all here to learn.

To really understand the exact reason as to why the machines are limited to exactly 3GB takes some understanding in the way hardware and software works, and I dare say that most people don't fully understand it, they've just accepted it as a fact a long time ago and stopped looking for workarounds.

But if you are really interested in getting to the bottom of it - I will try explaining again what me and others (e.g., twistero) tried explaining to you. However, please try to really understand it this time.

First of all, rest assured, that these are not mere guesses - the exact reason for the observed behavior is well-known and fully documented; it is just not very accessible.

Let's start with getting rid of some of the wrong assumptions you seemingly picked up during this thread:

dhinged wrote:the one bottleneck seems to be the chipset (I'm assuming dr_st meant the Intel 945 chipset) only working at 32-bit even with 64-bit Windows, even though Intel says it supports 4GB based on the "memory type" (DDR2-400/DDR2-533/DDR2-667), but I'm unsure of how to check which memory type I have in Windows 7 rather than pulling apart the laptop, but I'm assuming it's 667 because that's what the CPU's at (Intel Core 2 Duo T7400), but that's a 64-bit chip.

Yes, the 945 chipset is the bottleneck. However, the DDR speeds (which you refer to as "memory type" and the CPU bus speed have absolutely nothing to do with the 3GB/4GB limit. It's information that's completely irrelevant.

dhinged wrote:It is the 945 chipset, and the keyword that hit the nail for me was "virtual", in that "the virtual space between 3.5 GB of RAM and 3.75 GB of RAM is occupied by PCI Express data" and by virtual I'm assuming "on the hard disk when only 3GB of RAM is installed", so I'm assuming when 4GB is installed, it's actually using that area on the RAM... but maybe it's still using the hard drive, and that's what I'm not sure of in the article.

No, no, no. It did not hit the nail, it just confused you further. "Virtual" in this case does not have anything to do with the hard drive. Not with 3GB, not with 4GB - the PCI Express data the article refers to have absolutely no connection to the hard drive, and the sooner you forget this false connection you made in your mind, the better.

Now, the article did mention the correct thing. You just misunderstood it, as you have been misunderstanding our explanations in this thread so far. So I'll try to explain it with a bit more detail and precision than they did in the article.

The responsibility of the memory controller (which is part of the chipset) is to handle read/write accesses to memory addresses.

To say that the memory controller is 32-bit means that the addresses is recognizes are exactly 32-bit long, no more no less. With 32-bit you can have exactly 4GB different addresses, no more no less.

The tricky point here is that when I tell the memory controller - "I want to access address X", this address does not always point to RAM.

* It may point to RAM
* It may point to a physical device (the video adapter, the network controller, and basically any AGP/PCI/PCI Express device).
* It may also point to nothing (an invalid address)

The job of the memory controller is to understand what the address points to and implement the correct function to store/retrieve the data.

The devices I mentioned earlier must have some address space reserved to them. Otherwise programs cannot "talk" to them and they cannot function.

Note that I said - "address space", not "memory"! You don't need to reserve physical RAM. Think about it - if you buy and install a new sound card / network adapter - do you suddenly have less available RAM in your computer? No!

How does it work?

It works because the chipset has a special configuration setting (that's the TOLUD that was mentioned earlier), which tells something like this:

All addresses below TOLUD are physical RAM
All addresses above TOLUD are PCI devices (or unused)


Now let's go back to our 945PM chipset. Remember that its controller is 32-bit. This means that TOLUD must also be 32-bit, so somewhere between 0 and 4GB.

If you set TOLUD to 4GB you can have exactly 4GB RAM, but then you can't have any space for PCI devices, so they won't work. Bad idea.
If you set TOLUD to 1GB, then you have plenty of space for devices, but you don't need that much. And then you can only have 1GB RAM. Bad idea.

So where do you set it? You have to set it somewhere that make sense. 3GB was chosen as a good point, because:

* It leaves 1GB of address space for PCI devices, which is enough for all (or almost all) practical configurations these laptops can come with.
* It allows you to use as much as 3GB of address space for RAM. Of course if you have less, you will use less, but if you have more, you can still use the 3GB. Any RAM you have over 3GB will be seen as present in the system by, but inaccessible, because the addresses to access it have already been reserved to PCI devices.

Makes more sense now?

dr_st wrote: How does it work?

It works because the chipset has a special configuration setting (that's the TOLUD that was mentioned earlier), which tells something like this:

All addresses below TOLUD are physical RAM
All addresses above TOLUD are PCI devices (or unused)


Now let's go back to our 945PM chipset. Remember that its controller is 32-bit. This means that TOLUD must also be 32-bit, so somewhere between 0 and 4GB.

If you set TOLUD to 4GB you can have exactly 4GB RAM, but then you can't have any space for PCI devices, so they won't work. Bad idea.
If you set TOLUD to 1GB, then you have plenty of space for devices, but you don't need that much. And then you can only have 1GB RAM. Bad idea.

So where do you set it? You have to set it somewhere that make sense. 3GB was chosen as a good point, because:

* It leaves 1GB of address space for PCI devices, which is enough for all (or almost all) practical configurations these laptops can come with.
* It allows you to use as much as 3GB of address space for RAM. Of course if you have less, you will use less, but if you have more, you can still use the 3GB. Any RAM you have over 3GB will be seen as present in the system by, but inaccessible, because the addresses to access it have already been reserved to PCI devices.

Makes more sense now?

Thank you, explanations are better than condescension.

It's unfortunate Intel reports that it supports 4GB when it's not actually meaningful to a RAM-purchasing user (and I've seen Lenovo and other builders be wrong, ambiguous, or incomplete about specs).

ajkula66 wrote:

dhinged wrote:
So my question now is: is there actually any benefit to having 4GB installed,

No.

In terms of using 4th GB of RAM - NO BENEFIT.

But in terms of speed...
i945 can work at dual channel asymmetric mode. But asymmetric mode is slower than normal (symmetric) mode.
There is some date:
MemTest x86 v4.10, memory modules are samsung (2x1Gb) and kingstone (2x2Gb) 5-5-5 15, NOT Lenovo branded).
---------------
Memory config - speed
2x2Gb - 2319 Mb/s (only 3Gb can be tested)
1Gb+2Gb - 2076 Mb/s (asymmetric)
1x1Gb - 2073 (single channel)
2x1Gb - 2380 Mb/s
1x2Gb - 2168 (single channel)
All above tests at battery operated thinkpad.
And when i plugged in AC 2x1Gb grow to 2524 Mb/s. I think that other speeds grow proportional.

PS
Making Frankenpad it is the only way to eat 4Gb and more

ajkula66 wrote:But in terms of speed...
i945 can work at dual channel asymmetric mode. But asymmetric mode is slower than normal (symmetric) mode.
There is some date:
MemTest x86 v4.10, memory modules are samsung (2x1Gb) and kingstone (2x2Gb) 5-5-5 15, NOT Lenovo branded).
---------------
Memory config - speed
2x2Gb - 2319 Mb/s (only 3Gb can be tested)
1Gb+2Gb - 2076 Mb/s (asymmetric)
1x1Gb - 2073 (single channel)
2x1Gb - 2380 Mb/s
1x2Gb - 2168 (single channel)
All above tests at battery operated thinkpad.
And when i plugged in AC 2x1Gb grow to 2524 Mb/s. I think that other speeds grow proportional.

PS
Making Frankenpad it is the only way to eat 4Gb and more

Oh OK well I'll take the speed benefit; I want every last bit of power out of this thing.

Where would you recommend I look to make Frankenpad?

dhinged wrote:
Where would you recommend I look to make Frankenpad?

If your T60 is a 15" (4:3) unit, there's a ton of info on this forum when it comes to building FrankenPads.

If not, you're better off selling it and buying a 14" (4:3) T61/p.