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which cpu should I get?

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tryingagain

New Member
Joined
Dec 11, 2003
I am currently running a nf7-s board with a pally 2000+ chip, along with 512 4000 hyper x ram (getting 512 corsair 3200LLP), i want to overclock, so i would like to get a chip that is unlocked, I know about the bartons, and i like them, but the prices of 1700+'s and 1800's are very appealing. So my question is which processor is most likely to be unlocked and are there any advantagace of going with say a 1800+ over a 1700+, or say a 2100+, i have been researching and I see a lot of people getting different results, so in your opinion what (out of the t-breds) would be the one to get?
 

hitechjb1

Senior Member
Joined
Feb 2, 2003
For me, I would go the cheapest route, an unlocked Tbred B 1700+/1800+ DLT3C (if you can find them). Use the saved money to get a good HSF such as SLK-947U and TT SFII.

If you cannot find an unlocked CPU, and if your nf7-s and memory can run 210-230 MHz, a locked Barton 2500+ would be OK. But due to the locked CPU multiplier, it would be harder and less flexible to tune both the CPU and FSB to their optimal points.


Comparing Tbred B 1700+/1800+ DLT3C and Barton 2500+ overclocking performance, power and temperature (page 14)

Impact of Tbred B 1700+/1800+ DLT3C or Barton 2500+ w/ locked multiplier on overclocking (page 18)
 

hitechjb1

Senior Member
Joined
Feb 2, 2003
The DLT3C is labelled clearly by AMD on the chip package.

Or the online sellers or local stores should spell them out clearly.
 

hitechjb1

Senior Member
Joined
Feb 2, 2003
Originally posted by hitechjb1 (04-08-03 06:02 PM)
For Tbred B,
XP1700+ rated 1.5V is coded AXDA1700DLT3C
XP1700+ rated 1.6V is coded AXDA1700DUT3C
XP1800+ rated 1.5V is coded AXDA1800DLT3C
XP1800+ rated 1.6V is coded AXDA1800DUT3C

(For Tbred A, there are only 1.5V rated 1700+, 1800+. They have same code AXDA1700DLT3C and AXDA1800DLT3C also, so be careful. Have to use stepping code such as AIUHB, JIUHB and date to differentiate Tbred B from Tbred A.)

The L stands for rated voltage of 1.5V, the U stands for rated voltage of 1.6V, and K stands for rated voltage of 1.65V. There is no 1.65V rated Tbred XP1700+, XP1800+. The 1.65V is for TBRED B 2400+ and up.

They are based on 0.13 micron silicon technology, as the rest of the Tbred B siblings.

Acutally the lower voltage 1.5V Tbred B version, takes more current running at 1.5V compared to the DUT3C running at 1.6V !!! Both consume same rated power at their rated voltage.

E.g. from Tbred B datasheet, typical active current
1700+ @1.5V, Icc = 29.9A <--- DLT3C interesting, lower Vcore, higher current (or higher power/voltage)
1700+ @1.6V, Icc = 28.0A
1800+ @1.5V, Icc = 30.9A <--- DLT3C interesting, lower Vcore, higher current (or higher power/voltage)
1800+ @1.6V, Icc = 28.9A

This explains why the 1.5V Tbred B version can be overclocked to a frequency comparable to other XP, from 1700+ to 3000+ (and beyond, highest I heard is 3.1 GHz !!!), but at a lower voltage. This has something to do with the internal transistor characteristics, I suspect lower transistor threshold due to process variation. It remains to be seen whether it can be clocked at higher absolute clcok frequency (at higher voltage), compared to the 1.6V rated ones and the 1.65V bigger siblings, over a large sample.

Since it performs equally well at a lower starting voltage, it looks like it has the potential to become the top overclockers, provide that it can handle higher voltage without generating more heat per voltage due to leakage current, or no run away heat/voltage control problem.

Since the 1.5V can deliver similar clock performance at lower Vcore, there is a lesser need for a Vcore mod.

....