Hi there,

I've been fiddling around with my new system for a couple of weeks and the last thing remaining for me to do is to unlock the multiplier and set up CrystalCPUID. Any ideas about how best to unlock the multiplier? I've done a lot of google searches and there seems to be several different ways and I don't know which is best/ most reliable/ easiest (read safest).

Here are some I've found:
AthlonXP unlocking

similar but for Bartons

rather scary pinmod method

Any ideas on the best tool for the job - lead pencil, conductive pen, silver humbrol paint, carefully selected eyelash I want to make sure I've got this clear in my head before I even take the cooler off, so any help'd very much appreciated!

cheers
matt

Hi, as far as I'm aware all Athlons (apart from mobile ones) made after a certain point (about 2 years ago) are multiplier lock in a way that can't be unlocked. As you've found the older ones were or could be unlocked by various methods. I think you'll find with your Sempron it's multiplier locked and that's it. You can adjust the speed by changing the FSB.

Seb

that sucks SebRad, I didn't realise that (hence some of the confusion). I don't really want to permanently overclock the CPU, by raising the FSB freq. for eg., I'm more interested in using CrystalCPUID to dynamically alter the multiplier/ voltage so it sucks less juice when the CPU's idling but leaves me with a decent PC when I need it.

Hmm, more research needed i think!

You're both right and wrong. Yes, they're locked so you can't change multiplier in BIOS or with software in the OS. BUT, you can still mod it so you can control multiplier in Windows, but not in BIOS. It pretty much depends on which mobo you use. AFAIK, if you got the right mobo you can get this in Windows:
VIA, SIS: Multiplier control - Requires the mod I'm talking about. Doesn't work on many mobos.

nVidia: FSB control and Vcore control - Don't really know if you need to mod anything.

I used an Abit KV7 (VIA) together with a locked XP 2500+. It worked but it didn't really affect my every day use, and that is just because I had no Vcore adjustability. I was forced to use the Vcore needed for the highest setting in CrystalCPUID all the time (quite logical). Not really worth it IMO.
If I had to choose between them today I'd go for nVidia. Running at a lower FSB when idle or just web browsing doesn't really seem like a problem. I think people had problems changing FSB too much on the fly though, it could crash sometimes. Do more searching... or first of all, what motherboard are you using?

Oh right, sorry about that! Gigabyte GA-7VT600P-RZ Socket-A VIA/KT600, see here

Mats - is this mod you're talking about the bridge joining/ pin tying etc I was asking about in my 2st post? I've also just been reading about 8rdvacore, which allows VCore and FSB to be stepped according to CPU load. Looks interesting (and I won't have to worry about unlocking multipliers) but is purportedly less stable than CrystalCPUID. Thanks for the help!

As I said before, FSB and Vcore control (8RDAVcore) is for nVidia only! The VIA solution involves connecting bridges. While it's fairly easy to do the mod with conductive paint, it's not worth it IMO since you don't have Vcore adjustment available.

If you got heat/noise problems you should look at the heatsink, fan and fan intake. Maybe getting something better? Also lower Vcore in BIOS if possible, otherwise with pinmods (It's not scary! Connecting bridges are much worse, you risk getting paint somewhere it shouldn't be, not very likely with a wire if you can count socket holes.)

But first you should do this if you don't know what S2K is....



You may have S2K bus disconnect as an option in BIOS, check that first. AFAIK, S2K bus driving strength is not the same!

I've just bought used mobile-modded sempron 2400+ on net auction.

It is pencil trick modification. I can make a photo if you are intrested.
I don't have mobo yet thus i can't check if this mod is ok.

I've read that mobile-mod trick (unlocking multiplier) works only on non-nvidia chipset mobos (i.e. VIA, SiS).

I have to search and find that article/post.

sorry, the bit about VCore being NVidia only passed me by <slaps forehead> I think I can manually tinker with the FSB in BIOS (according to the MB manual), though from what I remember it's only upwards.

Cooler is an AC Copper Silent 2 and CPU temps (from MBM5) are 48 idle/ 53 load (so far) with a foam filter in place on the Chassis Air Guide (Antec SLK1650B). Taking the filter off drops the temperatures by almost 10deg C, but then I have to clean out the case every fortnight. Rear 120mm fan (Coolermaster) is currently at 5v and largely inaudible, at 12v the temps drop about 5deg but the fan adds a noticeable low level drone to the PC noise. At the weekend I'll rewire the rear fan switch to give 7v or 12v to see if 7v is a better compromise re cooling/ noise. CPU fan noise isn't too noticeable as the PSU exhaust fan is louder, though it'll be looking/ hearing at it again if/when I can get the PSU fans quieter.

That S2K mod looks awesome - many many thanks for that! I'd have never found that myself, so that's a great tip That's on the list of things to do at the weekend as well. I'll have a play around (as scientifically as I can) with VCore (BIOS), multiplier (if I can) and that S2K mod and report back next week.

Cheers!
matt

Verion - a pic of that would be very much appreciated thanks! The more information the better as I don't really have £45 hanging around if I balls it up

Ok. I'll post photo within few hours.

I'm planning to buy mobo next 1-2 weeks - then I can post my results.

You're kidding, right?
Maybe time to clean the room!
I had to clean it maybe twice a year or less, but then again I didn't have any case fans, only PSU and CPU fan. Uncontrolled case airflow is stupid! Power is nothing without control...

it's a combination of super dust bunny carpet and utterly shite mini-vacuum cleaner (we live in nearly the world's smallest flat and don't have room for a proper sized one!), so hoovering every weekend just keeps it at bay. Besides, if I put filters on my PC, then I just have to hoover my PC filters, right?

thanks for the S2K tip Mats, remind me to buy you a drink if I ever meet you - idle temp now down to 39 lovely degrees C! What a star!

you'll have to wait for photo of mobile-moded sempron till monday, sorry

Good news - i'll probably get my mobo till tuesday, so I can confirm if this mod is ok.

no worries

I couldn't find my camera
so I took one from the web.

You have to connect two little "holes" on the pcb (thick red line on the photo).

I my case whole light green rectangle area is filled with pencil (HB). (that rectangle with the red line within)



Now It's time to try this mod and see if it works
I'll post the results soon.

______________

So far so good. It is working. I didn't burnt anything
So I suppose this mod is perfectly safe.

[Of course YMMV, You are on your own. I'm not responsible for anything...blah, blah, blah.]


BIOS is showing standard (10x) multipier.

When underclocked @133x10 - bios is showing idle temp @ 29 'C (TT copper silentbooster + no name fan @ 5V)

I have to install system and CrystalCpuID to confirm that I have now mobile sempron. And try that s2k bus hack.

More on this later (1-2 weeks) because i have to finish my temporary htpc first.

EDIT: added results

thanks Verion!

that looks pretty simple to do, I'd love to hear how you get on with CrystalCPUID using the modded chip. This mod's next on the list of things to do, hopefully I'll have time at the weekend.