Thinkpad W500 with Core 2 Duo T9400 Engineering Sample CPU

[tudoranadi]

Hi folks!

Last month i bought a Thinkpad W500 from a unknown guy. The notebook has a Intel Core 2 Duo T9400 Engineering Sample CPU.
I read that this kind of CPUs have problems because are not part of consumer product.
Don't know if this is the cause of the problem but TPFanControl reads differently the CPU temp than Everest or RealTemp or AIDA64. Are with 10 degrees C higher.

The CPU acts and performs flawlessly. Didn't had any shutdowns or bluescreens.

Any thoughts?

Thanks!
http://i.imgur.com/x3U5bB1.jpg

[ajkula66]

Don't know if this is the cause of the problem but TPFanControl reads differently the CPU temp than Everest or RealTemp or AIDA64. Are with 10 degrees C higher.

Perfectly normal.

TPFC reads the sensor on the inside of the chip, other programs the surface temp.

[precip9]

There is an eBay scam selling an Apple pull for a CPU chip that is pin-compatible with the T9900, but draws 55 watts instead of 35. Since the power circuitry of the laptop can't handle it, the motherboard blows in days/weeks/months. The Intel p/n of this, if I recall correctly, is E8435, but the eBay sellers describe it as equivalent or identical. But it would show as a 3.06 gHz chip, while yours is a 2.53.

In the past, engineering samples have been problems, but that does not mean they are in this case. There is no rule. Only a development engineer who worked on the project or with the sample would know. The issue is this: the power control circuitry that makes the chip suitable for laptops did not have to work completely in an early phase engineering sample. It is also possible that dissipation figures were more tolerant, because in the early phase, the chip would be sitting in a bench setup, not enclosed in the laptop that would ultimately be designed around it.

Most reassuring, the T9400 was the mainstay, the most common 9X00 chip of that line. The genuine chip goes for about $20. See http://www.ebay.com/itm/Intel-CORE-2-DU ... 4d24db71ff

You could swap it.

[ajkula66]

There is an eBay scam selling an Apple pull for a CPU chip that is pin-compatible with the T9X00, but draws 55 watts instead of 35. Since the power circuitry of the laptop can't handle it, the motherboard blows in days/weeks/months. The Intel p/n of this, if I recall correctly, is E8435, but the eBay sellers describe it as equivalent or identical.

Some of us here have been running that chip on the *00 with no issues whatsoever...obviously, YMMV.

You've supplied a screenshot. Unfortunately, I have no idea how the E8435 is recognized by a software inventory program.

It is recognized as exactly what it is, and at proper (3.06 GHz) speed.

[Qing Dao]

There is an eBay scam selling an Apple pull for a CPU chip that is pin-compatible with the T9900, but draws 55 watts instead of 35. Since the power circuitry of the laptop can't handle it, the motherboard blows in days/weeks/months. The Intel p/n of this, if I recall correctly, is E8435, but the eBay sellers describe it as equivalent or identical. But it would show as a 3.06 gHz chip, while yours is a 2.53.

It isn't a scam. The E8435 that you mention, as well as the E8135, E8235, and E8335 are not a scam. Those processors all come in C0 and E0 steppings. The C0 steppings use a little more power and run hotter than the E0 steppings, as with any other Penryn processors. The E0 stepping E8435 is actually identical to the T9900. TDP does not equal power draw. It is just a guidline for the cooling system's heat dissipation. Anyway, their label and information in any software is always going to indicate their actually processor name.

In the past, engineering samples have been problems, but that does not mean they are in this case. There is no rule. Only a development engineer who worked on the project or with the sample would know. The issue is this: the power control circuitry that makes the chip suitable for laptops did not have to work completely in an early phase engineering sample. It is also possible that dissipation figures were more tolerant, because in the early phase, the chip would be sitting in a bench setup, not enclosed in the laptop that would ultimately be designed around it.


Most reassuring, the T9400 was the mainstay, the most common 9X00 chip of that line. The genuine chip goes for about $20. See http://www.ebay.com/itm/Intel-CORE-2-DU ... 4d24db71ff

You could swap it.

One has to be cautious when buying an engineering sample to make sure that it is an appropriate stepping and that it has functional temperature sensors. In the OP's case, there is nothing wrong. It is a C0 stepping Penryn, which kind of sucks, but it is identical to a non ES processor. I have a C0 stepping T9400 in the computer I am typing this on.

[tudoranadi]

My next move is to upgrade the CPU to a T9900. So anyone who wants to sell a Core 2 Duo T9900 please let me know!

Best regards!

[precip9]

It isn't a scam.

I stand by the accuracy my two points: Everyone: DO NOT BUY the E8435.

TDP is the relevant figure. It's not some harmless "guideline."

[ajkula66]

I stand by the accuracy my two points: Everyone: DO NOT BUY the E8435.

I really can't see the "accuracy" of this particular point. It's an opinion. No more, no less.

TDP is the relevant figure. It's not some harmless "guideline."

While this is true, the other side of the coin is that no issues have been reported by users who had actually installed the aforementioned CPU in their *00 series ThinkPads...

[precip9]

I stand by the accuracy my two points: Everyone: DO NOT BUY the E8435.

I really can't see the "accuracy" of this particular point. It's an opinion. No more, no less.

TDP is the relevant figure. It's not some harmless "guideline."

While this is true, the other side of the coin is that no issues have been reported by users who had actually installed the aforementioned CPU in their *00 series ThinkPads...

There is a post, on some forum, by some guy whose laptop power circuitry failed three weeks after the swap. I am unable to find it. However, I found a thread, http://forum.notebookreview.com/hardwar ... e8435.html , with a very precise description of the differences, which I quote:

*Begin quote*
The E8435 comes in TWO flavors: SLAQD and SLGEA. Forget about TDP. It's a very misleading number.

SLAQD is a C0 stepping. It runs hotter than any T series CPU. It's much less efficient at idle and load. Do not get this if you are concerned about heat.

SLGEA is an E0 stepping. It runs hotter than a T series CPU at idle, but at load it will run about the same temp. The reason for this is:

E8x35 CPUs lack DFFS and IDA. DFFS is dynamic FSB frequency switching. It downclocks the FSB on the fly to save power. You'll take a 20-40m battery life hit as a result. IDA is Intel Dynamic Acceleration. It overclocks a core by a 0.5x multiplier under single threaded loads. The BIOS can manage the power just fine. There are no issues since it's the same as a normal C2D minus these features.

This is not a desktop CPU. It's a mobile CPU with features stripped off of it outfitted for iMacs. It's the same core as a T9900 and runs only 0.0125V more than a T9900. The E0 stepping can be undervolted to 1.1000V just fine at stock speeds, and overclock slightly further than a T9900 because of the additional voltage headroom.

*End quote*

While this quote does not mandate impending doom, someone else on this forum has already referred to discussions on German forums of failures of the W500 graphics. The graphics chip shares the CPU heatpipes. So why enhance the possibility of what actually is being reported?

There is enough in the quote to make it clear that no stepping of the E8435 is the thermal equivalent of a T9900. Perhaps a reasonable use of the E8435 would be for a T400/500 that has only the integrated graphics. I wouldn't personally go for it, but I can see it as reasonable, considering how cheap such laptops might be.

[dsvochak]

I don’t have the knowledge to agree, disagree or criticize anyone’s assertions here. I am, however, puzzled.

A few posts up precip9 states: TDP is the relevant figure. It's not some harmless "guideline." In a subsequent post, precip9 quotes a comment stating: “Forget about TDP. It's a very misleading number.” TDP is apparently both “the relevant figure” and something we should forget about.

How can something be both “the relevant figure” and something we should forget about?

[precip9]

Dsvochak,
Engineers may think differently from Thinkpad hackers. TDP is provided to the designer of a new machine, so as to say, "You must design your cooling solution to handle this much heat, or it will fail in the maximum-use scenario", where the maximum use scenario is also defined by Intel. Given the known cases of whole lines of Thinkpads being vulnerable to overheating, it is apparent that even an engineer can disregard or make his own rules, subject to the influence of company executives who want a 5 pound package to have more specs than can be used with enduring success. This is why, for instance, some feel the Dell Precision laptops are better for true workstation performance, which can involve hours of number crunching with no rest stops allowed to cool down.

The Thinkpad hacker is responsible only to himself. If a Thinkpad hacker puts an E8435 in a laptop, and uses it to satisfaction, he isn't intentionally bending the truth when he says the TDP is irrelevant. But what he says is inaccurate from the standpoint of legitimate engineering. On the other hand, stating that some step of the E8435 is equivalent to a T9900 is a falsification.

So who do you want to listen to? It depends. If you want to stretch the bounds at minimal cost, bend your ear to the other guys. If you want a laptop that has the highest probability of working in a hot car, or sunlight, or stuffed into an unventilated corner, give my pov some consideration.

[dsvochak]

So who do you want to listen to?

In general, I’m not likely to give credence to the side asserting diametrically opposite claims as both being evidence their position is correct.

[precip9]

So who do you want to listen to?

In general, I’m not likely to give credence to the side asserting diametrically opposite claims as both being evidence their position is correct.

Since this is a technical question, your decision should be based upon facts. Who you credit with the answer is not important. Give yourself the credit.

[Cigarguy]

Forget TDP, GDP, ABC, test it for yourself in the machine and environment that you have. Everything else is dribble, non-trivial dribble but still dribble. Take your machine, insert favourite CPU then try to crash the system with Prime 95 and GPUZ. If machine/system is rock solid under one or both torture test(s) then you are good to go. Otherwise it doesn't mean anything.

[ajkula66]

Since this is a technical question, your decision should be based upon facts. Who you credit with the answer is not important. Give yourself the credit.

The only two *facts* that we have here are:

a) That the TDP of E8435 is higher than one of the T9900

b) That ThinkPad buffs have used E8435 CPUs on the *00 series machines with no problems to report.

If you want a laptop that has the highest probability of working in a hot car, or sunlight, or stuffed into an unventilated corner, give my pov some consideration.

In all honesty, in any set of extreme circumstances/environment, one is much better served by a ToughBook than by a ThinkPad.

Forget TDP, GDP, ABC, test it for yourself in the machine and environment that you have. Everything else is dribble, non-trivial dribble but still dribble. Take your machine, insert favourite CPU then try to crash the system with Prime 95 and GPUZ. If machine/system is rock solid under one or both torture test(s) then you are good to go. Otherwise it doesn't mean anything.

Fair enough.

Currently, the cheapest T9900 on feebay is $65, where E8435 is $40.

Everyone needs to decide for themselves what is the most important aspect of this story...and which approach they will follow.

[Qing Dao]

There is a post, on some forum, by some guy whose laptop power circuitry failed three weeks after the swap. I am unable to find it. However, I found a thread, http://forum.notebookreview.com/hardwar ... e8435.html , with a very precise description of the differences, which I quote:

*Begin quote*
The E8435 comes in TWO flavors: SLAQD and SLGEA. Forget about TDP. It's a very misleading number.

SLAQD is a C0 stepping. It runs hotter than any T series CPU. It's much less efficient at idle and load. Do not get this if you are concerned about heat.

SLGEA is an E0 stepping. It runs hotter than a T series CPU at idle, but at load it will run about the same temp. The reason for this is:

E8x35 CPUs lack DFFS and IDA. DFFS is dynamic FSB frequency switching. It downclocks the FSB on the fly to save power. You'll take a 20-40m battery life hit as a result. IDA is Intel Dynamic Acceleration. It overclocks a core by a 0.5x multiplier under single threaded loads. The BIOS can manage the power just fine. There are no issues since it's the same as a normal C2D minus these features.

This is not a desktop CPU. It's a mobile CPU with features stripped off of it outfitted for iMacs. It's the same core as a T9900 and runs only 0.0125V more than a T9900. The E0 stepping can be undervolted to 1.1000V just fine at stock speeds, and overclock slightly further than a T9900 because of the additional voltage headroom.

*End quote*

While this quote does not mandate impending doom, someone else on this forum has already referred to discussions on German forums of failures of the W500 graphics. The graphics chip shares the CPU heatpipes. So why enhance the possibility of what actually is being reported?

There is enough in the quote to make it clear that no stepping of the E8435 is the thermal equivalent of a T9900. Perhaps a reasonable use of the E8435 would be for a T400/500 that has only the integrated graphics. I wouldn't personally go for it, but I can see it as reasonable, considering how cheap such laptops might be.

I see the lack of IDA as a good thing. It never, ever helps. It is virtually impossible to run one core at full load and have the other idle, especially these days when everything is made to take advantage of multiple CPU cores. I have only had problems with it causing instability. I undervolt my processors, and IDA enable requires a lot more voltage to be stable. I always disable it by setting the maximum CPU speed to 99% in the power manager.

The lack of dynamic FSB switching is also a complete non-issue. No Core 2 processor has it. It is a feature of the motherboard and chipset.

And like with the person you quoted, I agree that TDP doesn't mean anything. TDP is a general guideline for the maximum heat dissipation the heatsink should be built to handle. Actual power consumption will always be less than this. In some cases, far, far less, and is some cases actually pretty close to the TDP. Power consumption of a processor is calculated as thus: Power = frequency x number of cores x (voltage)^2 x a constant that is different for each type and stepping of processor.

If two processors run at the same frequency, have the same number of cores, and have the same stepping, if you run them at the same voltage they are going to have the same power consumption. There is nothing magical about it. The minimum voltage that any given processor will run at for a given frequency is a luck of the draw, but unless they are being overclocked tremendously, the voltages will be extremely close to each other. This is definitely different from the stock voltage though, as any processor should have enough margin for error as they can't be thoroughly tested for that on the production line. However, they never set the voltage of any processor excessively high.

C0 stepping Core 2 processors just suck, and one should stay away from them at all costs, so that is probably why there is a lot of fear of the Apple-specific Core 2 mobile processors. They can come clocked quite high, with the C0 E8435 being the same speed as the C0 stepping X9100, which is also a complete dog. If anyone actually intends to pay money for a Core 2 processor, they should only go for E0 and R0 stepping chips. Even the C0 stepping T9400, which is only 2.53Ghz, runs extremely hot in my T500.

The real lesson should be to just stay away from C0 (or M0) stepping Penryns.

[tudoranadi]

That's why i had an impression that my T9400 ES C0 stepping is getting hotter in my W500 than the others T9400. Good to know!


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