Optiplex 740 Processor Upgrade

Bios should be upgraded BEFORE changing CPU.  Otherwise you can have a system that wont even boot.

BIOS - BIOS

http://downloads.dell.com/firmware/O740-227.EXE

Processors are not mechanical or chemical engines.  They do not go into thermal runaway.  They DO Burn up and die with improper heatsink mouniting and or lack of thermal compound.

Higher performance Heatsinks are not like the aluminum versions.  They have copper heat pipes.

These are usually for 130W processors vs 65W or 95W processors.  The POWER SUPPLY must be larger for some which is why QUADS DO NOT GO INTO USFF versions and or may require a TOWER 305W or greater power supply.

Changing the CPU is not validated or supported by Dell.  Which ones work or are Validated with the latest bios can be found by asking Chiris M what the Dell part numbers are.  Same with the heatsinks.  There are REQUIRED copper performance heatsink upgrades so it is NOT possible that the cheap aluminum heatsink is used with 85W+ and up cpus.

 Spec lists these

I found this on eBay Dell Optiplex GX740 CPU Heatsink 0DT221 DT221 JX469 C6119

I don't see a fan, am I correct? Is it fanless system? Or I am missing something?

Any better picture would be nice, and the size.....

Edit. Completely proprietary fan, Dell Optiplex 740 CPU Cooling Fan Y4574 H9073 G9096 120x38mm 5-pin/4-wire

There is a difference in size of the 65 watt CPU and 95 watt CPU, so 89 watt would require small CPU cooler upgrade, I need to find your motherboard model to see the connections.

Dell-Optiplex-740-Desktop-Motherboard-YP696

What size of socket used here to attach CPU cooler? Any help?

I installed the 2.2.7 BIOS and had been using it for some time before the upgrade was attempted.

The old and new processors are both "AMD Athlon X2".  Here are the product pages:

http://products.amd.com/pages/DesktopCPUDetail.aspx?id=64&f1=&f2=&f3=&f4=&f5=&f6=&f7=&f8=&f9=&f10=&f11=&f12=

http://products.amd.com/en-ca/DesktopCPUDetail.aspx?id=451

My reasoning behind the selection of the ADV6000IAA5DO.  The word "Enhanced" does not appear on the BIOS splash screen, indicating I have a motherboard with the 4Mb flash and therefore cannot support a Phenom processor.  The 6000 is the fastest readily available processor at the 65W or 89W power levels.  The power supply is rated at 275W and my system, including monitor, has never exceeded 150W.

And now that I have the processor I have three more datapoints:

1) The BIOS correctly identifies the processor. GOOD

2) The system boots cleanly and runs. GOOD

3) The processor overheats. BAD!

So for me the big question is "Is the new processor bad or incompatible?".  It is a used processor of unknown origin.  The fact that it does power up means it will probably pass any test a recycler would perform.

Bipolar structures in semiconductors will go into thermal runaway when the thermally generated hole/electron pairs are sufficient to turn the device on.  What I don't know is if it's possible to experience such an event and retain some functionality.

Here are some pictures of the stock heatsink I'm using,note the copper heat spreader and heatpipes:

I unmounted, cleaned and remounted both processors more than once without affecting the result, other than the first remount of the old processor showing a moderate reduction in temperature.

What I am trying to find out is the way it mounts on top of processor, meaning, getting more efficient cooler, attaching Dell fan (since it has proprietary connector). My Inspiron 570 also have similar mounting - holes, I had motherboard back plate which I removed, my mounting socket is LGA775 (eventhough my processor is AMD as yours). Now we need to find out which LGA your MOBO has.

It's basically the same cover you show.  The back end of the cover pivots on the smaller plastic piece shown in your pictures and the front is held down to the motherboard by two screws.  The fan sits directly behind the computers front panel and is shrouded by the part of the heatsink cover that projects past the front of the heatsink.  So the fan exhaust is forced across the heatsink fins.  If you run the performance test you can hear the fan speed up with the processor load.  The clamping force that holds the heatsink against the processor comes through the plastic cover from the four screws that hold the pivot and cover down.  My motherboard is just like the one in your picture, and the processor socket is AM2.

Chris

"Bipolar structures in semiconductors will go into thermal runaway when the thermally generated hole/electron pairs are sufficient to turn the device on. "  True

However Its not a Bipolar Transistor its MOSFET design.  Silicon shows a peculiar profile, in that its electrical resistance increases with temperature up to about 160 °C, then starts decreasing. This would be a one way trip. The max temp for the cpu is 65 °C so going to 160 °C would fry the cpu. FETs are sometimes called unipolar transistors to contrast their single-carrier-type operation with the dual-carrier-type operation of bipolar (junction) transistors (BJT). Thermal runaway WILL destroy transistors and would not be a repeatable action.

NPN and PNP transistors are bipolar junction transistors, They are made with both P and N doped semiconductor material (usually silicon). In the NPN transistor the majority carriers are electrons in the collector and emitter N doped silicon and holes in the P doped base. Conventional current flows into the base supplying it with holes, some of these holes cross the base emitter junction. where they combine with the emitter majority carriers, electrons. However most of the holes meet their demise in the base itself combining with electrons that have crossed from the emitter. The emitter current is larger than the base current, and the majority of the emitter electrons that enter into the base end up drifting across the collector base junction. PNP transistors have electrons injected into the N base and holes injected into the P emitter. Base current controls collector current. The FET has either a P or N channel, thus they are unipolar. The gate voltage either creates the channel (enhancement mode MOSFET;'s) or pinches off the channel ( depletion mode MOSFET's and JFET's). The enhancement mode MOSFET doesn't conduct till the channel is created. JFET's and depletion mode MOSFET's conduct until the channel is pinched off. The FET is voltage controlled and the BJT is current controlled.

The OP Keeps going to Thermal Runaway.  If it did happen it would be one time.

:emotion-3:

Only Dell aka Chris M could answer the compatability issue. 

I'm not Dell Engineering and I don't play a dell engineer on TV either.

:emotion-4:

@SpeedStep: is that Niagra Falls even applicable here? Would you better advice on the cooler with all your experience?

I would say that the reason its not working is due to Power Supply Shutdown not Thermal Shutdown.

CPU 101 increase the MHZ increase the power demand on the VRM's

Type CPU / Microprocessor

Market segment Desktop

Family AMD Athlon 64 X2

Model number   6000+

CPU part numbers ADV6000IAA5DO is an OEM/tray microprocessor

ADV6000DOBOX is a boxed microprocessor

Stepping code NAAFG

Frequency   6000+ (rated)

3100 MHz (real)

Clock multiplier   15.5

Package 940-pin organic microPGA

Socket Socket AM2

Architecture / Microarchitecture

Microarchitecture K8

Processor core   Brisbane

Core stepping   G2

Manufacturing process 0.065 micron

221 million transistors

Data width 64 bit

The number of cores 2

Electrical/Thermal parameters

V core   1.1V - 1.4V

Maximum operating temperature  ? 62°C

Thermal Design Power   89 Watt

Spec Lists these as compatible.

@SpeedStep: well, I know where you can help here? Which other models use this motherboard? OP can not be the first one with this issue and that old model.

In Inspiron 570 case, some users were placing 125 watt processors without upgrading power supply, a jump from 65 watt, I know that our PSU is a bit stronger, but CPU has more watts as well?

I am not answering this.  I am not Validating an unsupported processor.

I do not work for dell.  This is Not supported nor is it covered under Warranty.  There are Lots of "ifs" but there is no clear "supported".

I'm definitely not on the hook for whether or not any processor is GOOD or BAD from a 3rd Party.

Questions were asked as to why its not working.  They have been answered.

Throwing in thermal runaway is a red herring.:emotion-14:

There is a GOOD REASON why the X2 5600+ is listed as MAX.

Can you say Not Validated?

Can you say OVERHEATING? The listed processors are 1.5v  the

Not working Processor is 1.1v It takes a great deal of effort for the

VRM to Reduce the voltage to 1.1v when 1.5v is the norm.

Can you say OVERHEATING? The listed processors are 1.5v  the Not working Processor is 1.1v It takes a great deal of effort for the VRM to Reduce the voltage to 1.1v when 1.5v is the norm.

Where 1.5V came from, I see majority in 1.20-1.25 and 1.25-1.35 ranges, not working has 1.1-1.4 range. Let him run CPUID and post pictures, this will answer a lot of questions.

One last question regarding the list you provided SpeedStep. Those Athlons are Brisbane or Windsor?

I just installed a recycled Athlon 64 X2 6000+ processor into my 740.  It's the 89W version, not the 125W.  The processor I'm replacing is a 65W 3800+.  The BIOS recognizes and identifies the new processor correctly.  The system boots (faster) and runs stably for the first few minutes but then the temperature starts to spike.  Up until that time the temperature is constant and moderately hotter than the 3800+ (seems reasonable, 89W vs. 65W).  I've swapped between the two processors several times, recleaning and reapplying thermal compound each time, without changing the outcome (other than a slight reduction in the old processors temperature).   I have the latest BIOS.  The fans are all turning and moving air.  The automatic fan speed control is behaving correctly. At this point I have three questions: 1) Does the fact that the BIOS recognizes the 6000+ and the system boots cleanly mean that the 6000+ is actually compatible with my motherboard? 2) Do processors fail in this way, run fine but then go into some sort of thermal runaway? 3) Can the same heatsink that's been untouched for 4+ years and full of dust work for a 65W processor and then fail with an 89W processor after a thorough cleaning? Chris

Since situation is not going to be solved quick, please provide me (SpeedStep is most likely out from this post, no offense, I understand) with the following.

I need you to get and Run CPUID and post a picture of the first CPU tab for each processor. I am not sure yet, but it seems that you might got the wrong processor. There are 2 6000+ processor families Brisbane (the one you got) and Windsor. Brisbane is 65 nm and Windsor is 90 nm. Now it is all depends on your original 3800+, it could be from any of those above mentioned. If you MOBO supports only 90 nm, you can not use 65 nm. This alone can cause your problem.

So lets verify this part. CPUID will clarify this on the first run. If you have now 3800+ installed, that could be enough, so we can see which one you have.

Also, have you lost too much with 6000+ already?