Thinkpads Forum

Is there a difference between T8300 and T9300 when it comes to heat?

I wan't a completely silent T601 with fans at 1500 rpm or so, my T60 can do this only I need the extra RAM with the T61 motherboard but I can't decide on CPU.

Both CPUs were made in 45um process with a TDP limited to 35Watts, 800 MHz FSB and 1.0 - 1.25 VID. There are two important differences between these models: T9300 has doubled cache memory and 100MHz faster clock speed. To answer to your question it is best to understand physics first. I'll quote Wikipedia:

The dynamic power (switching power) dissipated per unit of time by a chip is C·V^2·A·f, where C is the capacitance being switched per clock cycle, V is voltage, A is the Activity Factor[1] indicating the average number of switching events undergone by the transistors in the chip (as a unitless quantity) and f is the switching frequency.

As you may see C and A shall be constant here, so is voltage (VID). Considering that fact you shall realize that disparity in heat generation is linearly dependent on the frequency. In this situation increase of of heat generation shall not be higher than 1/25, so theres nothing to worry about.

Pokrzept wrote:Both CPUs were made in 45um process with a TDP limited to 35Watts, 800 MHz FSB and 1.0 - 1.25 VID. There are two important differences between these models: T9300 has doubled cache memory and 100MHz faster clock speed. To answer to your question it is best to understand physics first. I'll quote Wikipedia:

The dynamic power (switching power) dissipated per unit of time by a chip is C·V^2·A·f, where C is the capacitance being switched per clock cycle, V is voltage, A is the Activity Factor[1] indicating the average number of switching events undergone by the transistors in the chip (as a unitless quantity) and f is the switching frequency.

As you may see C and A shall be constant here, so is voltage (VID). Considering that fact you shall realize that disparity in heat generation is linearly dependent on the frequency. In this situation increase of of heat generation shall not be higher than 1/25, so theres nothing to worry about.

But there is also a static power loss which I think will increase with larger L2 cache. From the quoted Wikipedia article: "The power loss due to leakage currents in contemporary CPUs and SoCs tend to dominate the total power consumption."

100mhz is not going to make a difference in heat generation (less than 10% increase in clock speed). The additional cache is what increases performance of the 9300 vs 8300. The Core 2 Duo CPU was when Intel turned the tables on AMD.

lab wrote:

Pokrzept wrote:Both CPUs were made in 45um process with a TDP limited to 35Watts, 800 MHz FSB and 1.0 - 1.25 VID. There are two important differences between these models: T9300 has doubled cache memory and 100MHz faster clock speed. To answer to your question it is best to understand physics first. I'll quote Wikipedia:


As you may see C and A shall be constant here, so is voltage (VID). Considering that fact you shall realize that disparity in heat generation is linearly dependent on the frequency. In this situation increase of of heat generation shall not be higher than 1/25, so theres nothing to worry about.

But there is also a static power loss which I think will increase with larger L2 cache. From the quoted Wikipedia article: "The power loss due to leakage currents in contemporary CPUs and SoCs tend to dominate the total power consumption."

I worked in CPU design (TTL logic) years ago and was later a CMOS ASIC design engineer. That statement is completely wrong, for normal CMOS technology. The current (and thus power) should drop to zero at zero clock rate. The leakage current is measured with the clock stopped. Heat is generated by the resistive losses in the transistors when they are required to charge the interconnect and junction capacitances for any change in state 0 to 1 or 1 to 0. It is theoretically linear with frequency until the point where the pull up and down transistors are unable to keep up with the changes in state and they both remain on fighting each other for part of the clock cycle. This is sometimes called mutual conduction. Power consumed and dissipated is all about changing state or dynamic switching.

Cache memory uses a lot of transistor and makes up a very large percentage of the die, it is possible that there is a large difference in power but they might have used some tricks in the cache to minimize the increase in power. Has anyone compared them in real world use?

I can give you a much less scientific answer but one based on literally building hundreds of T61 series laptops and providing parts to repair them or building frankenpads and the T8100/T8300 use less power and are more efficient than the T9300/T9500 series. If you want performance go with the latter, if you want a cool running laptop that has longer battery life, than the former is the ticket. The T8100 is believed by many to be virtually identical to the T8300, but underclocked so they could make an entry level penryn cpu and this theory would seem to be confirmed by the fact that you can run them at 110% of clock speed with little or no difference in temp using the popular app "throttlestop" whose developer selected the T8100 to use when developing the dual IDA mode function which changed it's design from being able to run the chip at 110% of clock speed when only one core is used, to being about to run both cores at 110% (requires middleton bios and throttlestop app on a t61 or similar series). Of course the t8100 is also an inexpensive chip so you really can't be it's cost, efficiency and thermal properties, and as with all penryns, they run very cool, but these are the coolest. There are also some 6000 series penryns that I'd told will run in these laptops, but I haven't tried any of them and only these four were factory equipped. I don't really have an engineer's level of understanding of how these chips work, but I've spent countless hours testing these laptops to source motherboards for Frankenpad or other builds and learned a lot about their thermal properties. As far as motherboards go, for temperature and efficiency you cannot be the Intel graphics, but there are now available brand new NOS nvidia boards manufactured in 2011-2012 with updated gpu chips mostly from 2010 era that run much cooler than the 2007-8 boards and have native penryn support. I also have some intel boards with penryn support, used, lenovo refurbished, and I think there is one new NOS left, but the real bargain is the NOS nVidia boards as none of the much loved standard screens came with the new gpu chip, but if graphics aren't important to you and running cool is, intel might be the way to go an you could save some money going with a merom board and reflashing it with middleton bios so it won't generate the dreaded "thermal sensing error" on boot when running a penryn cpu chip.

Happy Frankenpadding.

I would not really bother myself when it comes to cpu temperatures when it comes to an frankenpads. I do own two t61/T9300/nV140m - one in 14,1 factory shell and one in T60p 15" shell - and none of them has any thermal issues even under long heavy load. Both of them run with an factory heatsinks and undervolted CPU (1.0V) and GPU (0.95V) at nominal speeds. Due to Windows7 Windows Update cock-up I have my CPU stress-tested every Tuesday and with a constant maximum load for few hours my frankenpad hits maximum temperature of 75 Celsius degrees without fan going frenzy (steady 3200 rpms). Before you may your call please do mind that software developers do everything they can to make our beloved platform obolete - lately i do have a problem with a stable framerate of 720p videos @ youtube and vimeo. Due to that higher clock and bigger cache buffer may really matter in the long run.

Thanks all, I bought a T8300 on Ebay. A completely silent frankenpad is my number one prio and less heat means lower fan speed.

My T9300 runs ice cold on the T61p even under heavy load. The bigger issue on these is actually the graphics processor, which gets very hot under load, but there's not too much that can be done about that.

I have T61's with both the T8300 and T9300. I don't notice much of a difference between the two processors. I do not think you can go wrong with either. It would be nice if they had a broadcom PCI-e card that would do both the graphics acceleration and wifi in one card. The T61 can take on youtube videos but does struggle a bit at times because of the 720p and above videos. From my understanding those with the broadcom video acceleration card churn through any content up to 1080p but have to use either ethernet or a USB wifi card for internet. With an SSD, the T61 is still a competent performer as an everyday use thinkpad.

Hans Gruber wrote:I have T61's with both the T8300 and T9300. I don't notice much of a difference between the two processors. I do not think you can go wrong with either. It would be nice if they had a broadcom PCI-e card that would do both the graphics acceleration and wifi in one card. The T61 can take on youtube videos but does struggle a bit at times because of the 720p and above videos. From my understanding those with the broadcom video acceleration card churn through any content up to 1080p but have to use either ethernet or a USB wifi card for internet. With an SSD, the T61 is still a competent performer as an everyday use thinkpad.

Video acceleration on the wireless card?! I don't know about the base T61, but the '61p can handle 1080p HD video and even some lighter or older games with no problem (although I'm not a PC gamer by any stretch of the imagination, so take that for what it's worth). That said, I didn't notice a huge difference going from the T7700 to the T9300, but I can't say that I'm displeased with how this (nearly) 8-year-old computer performs running Windows 10 and 3 monitors (achieved using the dock and the Plugable Uga, which is a USB DisplayLink card). It does everything that I need.

The T7700 with intel GMA was just enough to play 1080p video without frame drops. With a T9300 or T9500, there isn't a problem. Even 720p 60fps videos run without a hitch, and I would imagine an nvidia equipped motherboard to do even better.

The capabilities of these machines is astounding considering their age and ancient looks. You really can't say the same for the Pentium M machines that were only a couple of years older at the time.

I have plenty of examples from the T7700 up to the T9700. I also have the T410/420.

Thing is I dont think any of the C2D processors at hot in the least. The T410 family kills it as far as heat goes... as does my Q9100 example.

IMO all of my T9300-T9700 examples are fast everywhere.... but you're better off in Win7 classic mode rather than Win10.

The T7700/T8300s I have are probably hampered by bad architecture... the cpus are fine themselves but I think the DDR2 and the poorer Intel integrated gpus make them feel bad.

I seem to recall my T61 T7700 Quadro 140 whatever was an able performance in Win7. I did FHD video fine... maybe the Nvidia gpu helped things becuase any of this age with the Intel gfx isnt too fun compared to something in the T9000 class.

TonyJZX wrote:I have plenty of examples from the T7700 up to the T9700. I also have the T410/420.

Thing is I dont think any of the C2D processors at hot in the least. The T410 family kills it as far as heat goes... as does my Q9100 example.

IMO all of my T9300-T9700 examples are fast everywhere.... but you're better off in Win7 classic mode rather than Win10.

The T7700/T8300s I have are probably hampered by bad architecture... the cpus are fine themselves but I think the DDR2 and the poorer Intel integrated gpus make them feel bad.

I seem to recall my T61 T7700 Quadro 140 whatever was an able performance in Win7. I did FHD video fine... maybe the Nvidia gpu helped things becuase any of this age with the Intel gfx isnt too fun compared to something in the T9000 class.

Earlier I fired up one of my T61's. It has the T9300, 4GB of ram and a 120GB SSD with Nvidia graphics. I think the reason why the T61 model still does so well is because of the Core2Duo architecture. That was the CPU that intel introduced after being trounced for years by AMD .

A laptop really only needs 4GB of ram. It's the addition of an SSD drive that makes an old laptop like the T61 still capable. I do not see much of a difference between the T8300 and T9300 CPU's. I do see a significant difference between the discrete graphics and integrated graphics in the T61.

Hans Gruber wrote: Earlier I fired up one of my T61's. It has the T9300, 4GB of ram and a 120GB SSD with Nvidia graphics. I think the reason why the T61 model still does so well is because of the Core2Duo architecture. That was the CPU that intel introduced after being trounced for years by AMD .

A laptop really only needs 4GB of ram. It's the addition of an SSD drive that makes an old laptop like the T61 still capable. I do not see much of a difference between the T8300 and T9300 CPU's. I do see a significant difference between the discrete graphics and integrated graphics in the T61.

Yeah, computer software is still written pretty efficiently. It's not like on Android where these massive applications get slopped together that all seem to run in the background, demanding ludicrous amounts of RAM just to provide a decent experience.

That said, my T61p still performs respectably with a hard disk drive. It's only a 5400RPM Samsung, but it's one of the fastest laptop disks I've ever benchmarked, with 50-115MBps read speed, and it feels the part. It wasn't until I started benchmarking that I realized just how big the performance gap is between some of these laptop drives, and it's up to more than just rotation speed.

It just goes to show that every part is important - the chipset, the graphics, amount/speed of memory, and speed of the storage medium, in addition to the CPU of course.

Hello,
I also looking for some CPU update and still not decided between performance of T9300 and longer battery life with T8300. My question is how big is diffence in power consumption between these two CPU, in % or minutes (e.g. with standard 4-cell battery)?

One more question. I got this http://s13.postimg.org/mcjdsihx3/20160920_213448.jpg (right one) heatsink 44C0558 from another 14,1" T61, I read it could be better in cooling then older (left one). But it is for model with discrete graphic card... it looks very similar but I'm not sure I can use it in my T61 with integrated graphic (maybe small height difference in pad covering gpu). What's your suggestions?

Kulich wrote:Hello,
I also looking for some CPU update and still not decided between performance of T9300 and longer battery life with T8300. My question is how big is diffence in power consumption between these two CPU, in % or minutes (e.g. with standard 4-cell battery)?

One more question. I got this http://s13.postimg.org/mcjdsihx3/20160920_213448.jpg (right one) heatsink 44C0558 from another 14,1" T61, I read it could be better in cooling then older (left one). But it is for model with discrete graphic card... it looks very similar but I'm not sure I can use it in my T61 with integrated graphic (maybe small height difference in pad covering gpu). What's your suggestions?

I have done tests side by side comparisons with some of my T61 models. With and without discrete nvidia graphics. My T9300 primary T61 has Nvidia graphics and I have several T8300 T61's with discrete and integrated graphics. The T9300 does run hotter than the T8300. I use TPfanControl and it never seems to run up to 5K on the fan and the T9300 will creep into the low 80's when running youtube videos and playing a Sim City like game called Forge Of Empires. The T8300 machine stays in the mid to upper 70's under heavy load. If the T9300 has max fan speeds the CPU temps are in the high 70's. These are under very heavy CPU and GPU loads.

The post above by Tuus stating the T9300 runs hotter and takes more power than the T8300. I share a similar opinion in that regard. With the price of the T8300 being $10 or less on ebay. I think the T8300 is probably the processor of choice unless your T61 is mostly connected to the power supply.

Hmm...

I was pretty sure I had my CrystalHD in the other slot, the one that saw use for the mobile data/GPS from the factory.

I took it out when I was rejiggering the insides and didn't put it back in. I'll have to see if there are Win 10 drivers for it, find the card, and reinstall it.

Actually I may have to go back to 7 as the NV drivers for 10 are causing me headaches. Ugh... I had forgotten about that problem... lol

How much difference between T8300 and T9300 are we talking about? Five watt? Two? One?

Both are 35W TDP. However the T9300 is slightly faster with double the L2 cache size. I prefer the T9300.

http://ark.intel.com/products/33099/Int ... 00-MHz-FSB
http://ark.intel.com/products/33917/Int ... 00-MHz-FSB

Yes, but same TDP says little about idle energy use.

Other than L2-cache, there is not much difference: http://cpuboss.com/cpus/Intel-Core2-Duo ... -Duo-T8300

TuuS and Hans Gruber have both posted that the T8300 uses less energy. But how much less? The T9300 has double the cache and 100 MHz more

In my experience with a limited sample size of a few T61. The differences between a T8300 and T9300 is negligible. I think a lot depends on usage requirements. Need more computing power? T9300 by a slight margin. Need more power efficiency? T8300 by a slight margin. Idle speed depends on background processes and OS efficiency and will vary from one machine install to another so it's hard to compare. Same with max speed.

For an old machine, I wouldn't over think it. A T8300 or T9300 will both work great, get what is readily and cheaply available, use and enjoy. Need more computing power and/or efficiency? Look at a Sandybridge or newer machine.

Upgraded T7300 > T9300 and re-oiled the CPU fan.

Gained the ability to play 1080P Youtube movies.

^
Good to hear that.

Although at first boot, Windows still saw a T7300, and CPU-Z saw a T9300 running at 2.2 GHz. A shutdown + boot fixed that. Now T9300 @ 2.5 everywhere.