Old Dell Laptop - Memory Speed

nheather

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Hi,

I have just resurrected an old Dell laptop - it is a Dell XPS 1640, about 10 years old but still fairly decent.

I’m going to use it to support my hobbies, a portable computer that can be near my 3D Printer or radio control models.

I’ve probably gone over the top on the refurb, cleaned down the OS and file-store, upgraded to Windows 10 (free), put in an SSD (£16) and upgraded the RAM from 4GB to 8GB (£17.50).

It is the RAM upgrade that is a little disappointing and on reflection, not really needed. But what is bugging me is the speed it is running at 800MHz.

It is 1600 MHz stuff, and using CPU-Z I can see it has a whole range of lower alternatives in the SPD. But it only runs at 800MHz and there appears to be no way in the BIOS to change this. I have the latest BIOS.

I’ve googled and it seems that the laptop should support 1066 and 1333, and the original should have been 1066.

So appreciating that it wouldn’t run at 1600 but frustrated that I can’t get it to go at 1066 or 1333 even though they are in the SPD. So popped the original 4GB back in and noticed that is also running at 800 even though it should be 1066. When purchased this would have been running at 1066 because that was the sales specs.

So wondering there is some other way to select the RAM speed - other than the BIOS.

Any ideas?

Cheers,

Nigel
 
DDR3-1600 runs at 800Mhz. 1600Mhz is 'effective speed', i.e. marketing.
 
DDR3-1600 runs at 800Mhz. 1600Mhz is 'effective speed', i.e. marketing.

Yes I know that - it is running at 399 MHz - so performing as 800MHz RAM.

This is what is puzzling me. Had the new stuff run at 800MHz but the original at 1066MHz then I would have put it down as the motherboard/BIOS not knowing what to do with 1600MHz RAM.

But what is throwing me is when I put the original stuff back in that is running at 800MHz too. That is not how it was sold, so I wonder how Dell set the original stuff at 1066MHz. Maybe they have a utility or access to hidden BIOS options.

Cheers,

Nigel
 
According to the XPS 1640 setup manual (page 63) it is limited to DDR3 1066, other models in the Studio XPS 16xx series get the DDR3 1333 but not the 1640.

XPS 1640 memory config is limited to 1GB, 2GB, 3GB and 4GB.

8GB is limited to the other models, 1645, 1647.

Maybe this laptop only works with DDR 1066 with up to 4GB RAM ?
 
This is what I read on your system, taken from the Dell site and the last sentence, again from Dell's site, is the caveat to it running the 8GB of RAM.

Studio XPS 1640 supports DDR3 1066 MHz SODIMM memoryry speeds of 1066 / 1333 MHz.

Configuration greater than 4 GB will be supported only by 64 bit Operating Systems.
 
According to the XPS 1640 setup manual (page 63) it is limited to DDR3 1066, other models in the Studio XPS 16xx series get the DDR3 1333 but not the 1640.

XPS 1640 memory config is limited to 1GB, 2GB, 3GB and 4GB.

8GB is limited to the other models, 1645, 1647.

Maybe this laptop only works with DDR 1066 with up to 4GB RAM ?

This is what I read on your system, taken from the Dell site and the last sentence, again from Dell's site, is the caveat to it running the 8GB of RAM.

Studio XPS 1640 supports DDR3 1066 MHz SODIMM memoryry speeds of 1066 / 1333 MHz.

Configuration greater than 4 GB will be supported only by 64 bit Operating Systems.


But it is still puzzling. The original RAM that was sold with the Laptop is 1066, but when installed it is only running as 800.

My 1600 RAM works and passes the RAM tests, it has a 1066 profile in the SPD but that isn’t being selected.

I can get my head round (but am disappointed) that the 1600 is not being detected properly but really puzzled that the original 1066 isn’t detected as 1066.

Cheers,

Nigel
 
Your DDR3 1600 will work in the machine but will fall back to the max capability the MB supports. But as you say it's a little confusing as that rate is supposed to be 1066 according to Dell. This is a suggestion and only that, I can't see why this should be, but according to dell users has worked, try swapping the RAM modules around in their slots.
 
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Your DDR3 1600 will work in the machine but will fall back to the max capability the MB supports. But as you say it's a little confusing as that rate is supposed to be 1066 according to Dell. This is a suggestion and only that, I can't see why this should be, but according to dell users has worked, try swapping the modules around in their slots.

I can categorically say that my 1600 is not falling back to the highest supported by the board even though it has an SPD profile for that.

And more puzzlingly the 1066 sold with the laptop is also not running at 1066 either.

I will try swapping and combinations of single modules and report back.

Cheers,

Nigel
 
And more puzzlingly the 1066 sold with the laptop is also not running at 1066 either.

Yes it is confusing. Am trying to see if there is any particular reason/issue as to why this should be.
 
Another question ta ask here is what is the make/model of the RAM your using?

For example PNY MN8192KD3-1066, which is supported by Dell for your Dell XPS 1640 and is confirmed as working at 1066 in your lappy by other users.
 
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Tried every combination - all will only run as 399MHz (800 MHz).

And that includes the 1066 MHz modules that were in the laptop when Dell sold it.

I know that there is no such thing as 1066, 1333 or 1600 RAM, it is all 800 RAM that can run faster with slacker settings. My experience with desktop PCs that I built is that RAM usually runs at the low rate by default and has to be changed in the BIOS. But for this laptop there is nothing in the BIOS that allows any RAM settings.

This is why I was wondering whether there are any utilities or hidden BIOS settings that Dell might have used to set the RAM speed when sold.

Cheers,

Nigel
 
Another question ta ask here is what is the make/model of the RAM your using?

For example PNY MN8192KD3-1066, which is supported by Dell for your Dell XPS 1640 and is confirmed as working at 1066 in your lappy by other users.

As I said, I’m quite open to accept that the 8GB RAM I have just bought may not be fully compatible - it is much newer than the laptop. But really puzzled that the 4GB that was in the laptop when Dell sold it is not compatible.

It is

Hynix HMT125S6TFR8C

Cheers,

Nigel
 
According to the SkHynix site your modules are 2GB versions of their SODIMM RAM

In the number you supplied they have two variants:

Hynix HMT112S6TFR8C- G7/H9 1GB - - Data transfer rates: PC3-10600, PC3-8500, or PC3-6400

Hynix HMT125S6TFR8C- G7/H9 2GB - Data transfer rates: PC3-10600, PC3-8500, or PC3-6400

HMT125S6TFR8C < PRODUCTS < SK Hynix


This is their 4GB module

Hynix HMT351S6CFR8C - G7/H9 4GB - Data transfer rates: PC3-12800, PC3-10600, PC3-8500, or PC3-6400

HMT351S6CFR8C < PRODUCTS < SK Hynix

Is the model number you supplied your new RAM or original RAM as supplied by Dell? If new what was the model number of the old original RAM supplied by Dell?
 
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I gave you the original 2x2GB 1066 RAM - because I had said that I accepted the new 2x4GB 1600 stuff wouldn’t be listed as compatible because it post-dates the laptop.

My puzzlement is why the original RAM supplied by Dell doesn’t run properly as 1066. It has run as 1066 before so there must be a way of making it do it again.

My thinking is if we can solve that mystery then we may be able to apply the same solution to the new RAM.

1) original 4GB runs at 1066
2) remove original 4GB and fit newer 8GB
3) 8GB runs at 800
4) remove newer 4GB and refit original 4GB
5) original 4GB now only runs at 800

Question: what did Dell do to make the original run at 1066?

Cheers,

Nigel
 
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I notice you updated to the new BIOS, is that A15?

Just wondering if that update has caused the issue or did you have the same with the old bios version? Maybe Dell used a modified BIOS which was a tweak in their original BIOS.

Also did you update any drivers?
 
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I notice you updated to the new BIOS, is that A15?

Just wondering if that update has caused the issue or did you have the same with the old bios version? Maybe Dell used a modified BIOS which was a tweak in their original BIOS.

Also did you update any drivers?


Hi,

It has been on A15 for many years. The original RAM was working at 1066 on the laptop. It survived at least one BIOS update and remained at 1066.

It is only since I have removed it inserted the new stuff and then refitted the original stuff that it is refusing to run at 1066.

All I can think is that on most motherboards when you insert RAM and it is detected it will default to the nominal speed (800 in this case). If the RAM has a higher supported speed in the SPD then you have to select that in the BIOS.

The problem is that this BIOS does not have any functions to change the RAM settings.

So I'm guessing that Dell must have a utility or access to a hidden BIOS functions to change the settings of the RAM. All was fine until I used the new stuff which the motherboard defaulted to 800. Then when I put the original stuff back in the motherboard is also defaulting that to 800. And I have no means of telling the BIOS to use 1066 on either of my RAM pairs.

Cheers,

Nigel
 
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Yes it's a strange one. I know that Dell do stuff with their products that only they are able to do as they lock it out to the general user base. I can well imagine that they did a BIOS tweak, but what is baffling is such a tweak would revert from 1066 to the lower 800 by just inserting new RAM. Whatever they perhaps did would have been done at a chip level, the chip being blown with new firmware. I can't see how this could be changed by inserting the new modules but obviously something has happened as you are now where you are.

It's quite an interesting one so I will dig around and see if I can find anything further on it.
 
I get that you want to get the best out of the PC and the RAM in it, but in real terms does it matter?

https://www.howtogeek.com/303455/how-does-ram-speed-and-timing-affect-my-pcs-performance/
Honestly, it doesn’t mean a lot. While faster, lower latency RAM will indeed increase the technical performance of your computer, it works at such a fundamental level that it’s almost impossible for us flesh-and-blood humans to actually appreciate the difference. It’s like the comparing Data from Star Trek and C3P0 from Star Wars—if one can calculate the odds of survival in one billionth of a second and the other takes two billionths, does it really matter which one you ask?

Faster RAM will give your PC better performance in certain specific benchmarks, but in terms of actual benefit to most users, having more RAM available is almost always better than having faster RAM. So if you’re on the fence about purchasing 8GB of DDR4 RAM with a speed rating of 3200 or 16GB of DDR4 RAM with a rating of 2400, go with the second option every time. It also means that overclocking RAM in the system BIOS is rarely worth the effort.

Mark.
 

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