by DrPR » Sat Mar 27, 2021 12:34 am
Pascal.
The low price DesignCAD 3D Max that I use for CAD work does use up to five of the six cores (10 tasks) on my i7 desktop (Windows uses the sixth). I was surprised to see it doing this about 10 years ago but I guess it isn't too hard to accomplish with Windows 7 and later.
One thing to keep in mind about multiple core processors is that they generate a lot of heat when all are running 100% duty cycle, and things like rendering a 3D design can push them to the limit. I have a dual fan liquid cooler on the 4.2 GHz processor, and when all cores are running the fans start to roar!
The reason I mention this is that laptops do not have enough cooling capacity to cool the processor when all cores are running hot. For a while Apple issued a warning that it's laptops should not be held in the lap because you might be burned! When they get hot they slow down and the program really drags.
The Intel i5 and i7 processors have an additional embedded small CPU (one of the guys I worked with wrote part of the software for it) that monitors the temperature of all the cores. If the temperature approaches 60C this processor shuts off the clock to the core until it cools. It switches the clock on and off as necessary to control the heat. If that doesn't work the monitor processor drops the voltage in increments to reduce power. If it lowers the voltage too much the core crashes - blue screen of death (BSOD). But the CPU doesn't melt!
This caused a lot of laptops to suddenly stop working with the BSOD, and no one knew why.
On my machine with the liquid cooler the machine would suddenly start roaring like an airplane taking off, but it kept running. It it was strange - it usually happened on Wednesdays at about 10 AM, and only when the machine was running idle! I installed some debugging software and finally figured out that Microsoft scheduled disk defragmentation on the same day each week, at the same time, and it used all six cores at 100% duty cycle. But they only started this when the machine had been idle 30 minutes.
I contacted engineers I knew at Intel and told them what I had discovered, and I called Microsoft and let them know. They changed the way they defragmented disks (short bursts slipped in all the time). And no more BSOD. Because I had thermally stressed my CPU the fellow at Intel offered to send me a new $700 chip!
Laptops are a bad choice for demanding CAD jobs (any program that uses all the CPU cycles for an extended time).
Phil
Pascal.
The low price DesignCAD 3D Max that I use for CAD work does use up to five of the six cores (10 tasks) on my i7 desktop (Windows uses the sixth). I was surprised to see it doing this about 10 years ago but I guess it isn't too hard to accomplish with Windows 7 and later.
One thing to keep in mind about multiple core processors is that they generate a lot of heat when all are running 100% duty cycle, and things like rendering a 3D design can push them to the limit. I have a dual fan liquid cooler on the 4.2 GHz processor, and when all cores are running the fans start to roar!
The reason I mention this is that laptops do not have enough cooling capacity to cool the processor when all cores are running hot. For a while Apple issued a warning that it's laptops should not be held in the lap because you might be burned! When they get hot they slow down and the program really drags.
The Intel i5 and i7 processors have an additional embedded small CPU (one of the guys I worked with wrote part of the software for it) that monitors the temperature of all the cores. If the temperature approaches 60C this processor shuts off the clock to the core until it cools. It switches the clock on and off as necessary to control the heat. If that doesn't work the monitor processor drops the voltage in increments to reduce power. If it lowers the voltage too much the core crashes - blue screen of death (BSOD). But the CPU doesn't melt!
This caused a lot of laptops to suddenly stop working with the BSOD, and no one knew why.
On my machine with the liquid cooler the machine would suddenly start roaring like an airplane taking off, but it kept running. It it was strange - it usually happened on Wednesdays at about 10 AM, and only when the machine was running idle! I installed some debugging software and finally figured out that Microsoft scheduled disk defragmentation on the same day each week, at the same time, and it used all six cores at 100% duty cycle. But they only started this when the machine had been idle 30 minutes.
I contacted engineers I knew at Intel and told them what I had discovered, and I called Microsoft and let them know. They changed the way they defragmented disks (short bursts slipped in all the time). And no more BSOD. Because I had thermally stressed my CPU the fellow at Intel offered to send me a new $700 chip!
Laptops are a bad choice for demanding CAD jobs (any program that uses all the CPU cycles for an extended time).
Phil