New look of nokia n900's overclock
 

Hi there all,

First, I know that there is many topics about over-clock, many single post's what include people's manual and, of course, wiki page about it, but

None of these include something I want to be explained.

So, smart reflex:

I had at least a few n900 devices, and all of course I over-clocked.
But my last two (2) devices (I still have them, and those are not the youngest from my collection) I could over-clock over 900mhz (To the 1100mhz) with smart reflex on, and with many voltage profiles (Including my own), been using them for days without experiencing any problems, random reboots, slows down and so.

Before those two n900s over-clock over 900mhz with SR on will give me crash imidietley.

The n900 I use everyday I have fixed @950mhz with ideal voltage profile, smart-reflex on and never had any problems (Now for half a year)

My n900 is running maemo 5 with cssu update - maybe that's the thing? Did cssu bring something new about over-clock?

Re: New look of nokia n900's overclock
 

IIRC; there was speculation of a variance in the chipset between the N900s made in Finland and those from China. Nothing noticeable when running day to day applications but enough to see an effect when OC'd.

On paper the chips were identical, so it could have been a supplier or batch problem.

Re: New look of nokia n900's overclock
 

So, what can we tell, n900 aren't made equal, but there imho shouldn't be so noticeable gap between some.

How to check were my tablet was made? Should I go through papers? I know it's designed in Finland, hehe :D

But now, how it should be?

The n900, should go over 900mhz with smart reflex or they should not? What can we describe as "golden unit"? Is it even possible to describe?

And finally? What are those variance you mentioned?
Is it better circuit capacity? What I mean is, are those "better" units better handle higher voltages and frequency? Sorry for my unsettled describe, Im not an hardware engineer :P

Re: New look of nokia n900's overclock
 

Well we have to remember that Nokia never designed the N900 to run above 600mhz, so any stability issues that may have become apparent when overclocking at 900mhz were never considered 'defective'. These issues only came to light when we started overclocking our devices and from this user testing, it was assumed that not all n900s are built 'equally'.

The general consensus is n900s that are “Made in Finland” are the golden devices because of the QC tests taken in Nokia factories. However there are now many convincing fakes and refurb units out there that state “made in Finland” on the boxes that work just as well. So finding a genuine Finnish N900 in 2015 will be quite rare.

With that said, other users with n900s that were “made in china” (in including myself) can overclock up to and over 1150mhz. I preferred a manual approach then adding a queenbee OC widget to the desktop. I would like to ask if smartreflex is the only method you have used?


And finally... The variants in the CPUs are most likely a manufacturing fault in the batch process, were they have found that a certain set of gates in the microprocessor do not open as they should when called for.

This is a very common problem in chipset manufacturing. Intel have this too, and are known for 'down grading' their production batches. For instance, when running a batch of Pentium4 processors and they find they do not run to full capacity for that very same issue, they will not throw them away. They will just put a Celeron sticker on them. For Nokia, they negated this issue by designing the n900 to be stable at 600mhz*.

I hope that answered many of your questions. If I am wrong anywhere, there are more knowledgeable folk around who will correct me. And I do admit, much of what I have said is from following 5yr old threads. Things may have moved on a lot since I last booted up my n900.

Edit: *600mhz at stable was still beastly specs in 2009.

Re: New look of nokia n900's overclock
 

What do you mean by " smartreflex is the only method"?
I can only suppose that you thought that I was using some kind of program/widget/something like? - No no no, no such thing, only manual method, to be more specific, I created a multiple copy of overclock file stored in /home/user/.kernel/ adding different values. Some fixing my cpu at 950mhz, some jumping from 250-550 with 100 Powersave value, as you may think for battery saving.
I activate them through Desktop command execution widget, cause it's easer than doing so through X-Terminal itself.

Yep, heard some stories similar to one you described.

Everything you said was helpful, thank you for exhausting answer.

Yep, I'm fully aware of that, It was able to load full facebook page without any problem. Today, even for overclocked device this task is nearly impossible, but...

For n900 it was all right, but Im still gonna say that nokia could use better cpu unit and for sure they could do so for n9 (2 year younger device, nokia had some overdue, the n9 at first plans was supposed to be ready in 2010 but was released in 2011), which has only slightly better cpu (But running at higher freq.)
Ive read some stories, that n900 cpu overclocked to 1100mhz is almost equal with n9 cpu at stock 1000mhz.
So
N900 and N9 are both awesome unit, but they could've been better.

Re: New look of nokia n900's overclock
 

I know from experience that the chips vary; my first n900 was only stable up to 800 mHz, but the replacement I got is stable all the way to 1150 mhz.

Re: New look of nokia n900's overclock
 

Never experience that, I was able to overclock each one of my n900's to at least 1000mhz(Without SR), only difference I noticed was when OC with Smart Reflex.

I'm going to re-flash my n900 in few days and will check how OC works without CSSU patch.

Re: New look of nokia n900's overclock
 

SR only "supports" overclocking to 900Mhz
http://wiki.maemo.org/Smartreflex

Re: New look of nokia n900's overclock
 

Also SR and custom voltages MUST NOT be used together.

Re: New look of nokia n900's overclock
 

I just wrote the whole long post about it, it's the first of this topic. I know about supported freq with SR, but I also know, that my n900 runs fixed at 1Ghz with SR on and it's perfectly ok for about half a year, please, read all posts in this topic first.