Does anyone know the safe maximum current (amperage) limit of a Core i7-8700? I cannot seem to find this information in the Intel datasheets. I'd also like to know the default value.
I'm trying to undervolt an i7-8700 processor to reduce heat because of case size and constraints environmental factors. I'm trying to find the best balance between speed and heat.
Motherboard: ASRock Fatal1ty Z370 Gaming-ITX/ac
CPU: Intel Core i7-8700
All settings default
Stress tests: Prime 95 FFT, Blend
I've found a relative VCore undervolt of -50mV to be stable, but it still produces too much heat. The BIOS has additional settings which allow me to set a TDP limit and a maximum current (CPU Core Current Limit).
Setting the TDP limit to 125W brings the heat levels under control, but I'm concerned that the CPU current draw is being greatly increased to achieve this. The CPU current is being handled automatically by the motherboard. I believe it's increasing the current to compensate for the lower VCore in order to achieve the same frequency. Unfortunately, the BIOS doesn't tell you what the default value for current is.
If, on the other hand, I set CPU Core Current Limit to 135 without a TDP limit, it will cap the TDP around 126W under load. That would signify to me that it's drawing at least 135A above when the TDP is set to 125W and current is handled automatically.
Setting the current limit to 135A causes the FFT test to run at the same frequency as when using the TDP limit = 125W. However, the Blend test runs at a higher frequency when using TDP limit vs current limit, indicating to me that the motherboard is allowing the CPU to draw even more current than 135A when handled automatically. Therein lies my concern. Is 135A-150A+ safe for this CPU? I don't want to be shooting myself in the foot undervolting to reduce heat only to be killing the CPU by pumping too much current.
I'm trying to undervolt an i7-8700 processor to reduce heat because of case size and constraints environmental factors. I'm trying to find the best balance between speed and heat.
Motherboard: ASRock Fatal1ty Z370 Gaming-ITX/ac
CPU: Intel Core i7-8700
All settings default
Stress tests: Prime 95 FFT, Blend
I've found a relative VCore undervolt of -50mV to be stable, but it still produces too much heat. The BIOS has additional settings which allow me to set a TDP limit and a maximum current (CPU Core Current Limit).
Setting the TDP limit to 125W brings the heat levels under control, but I'm concerned that the CPU current draw is being greatly increased to achieve this. The CPU current is being handled automatically by the motherboard. I believe it's increasing the current to compensate for the lower VCore in order to achieve the same frequency. Unfortunately, the BIOS doesn't tell you what the default value for current is.
If, on the other hand, I set CPU Core Current Limit to 135 without a TDP limit, it will cap the TDP around 126W under load. That would signify to me that it's drawing at least 135A above when the TDP is set to 125W and current is handled automatically.
Setting the current limit to 135A causes the FFT test to run at the same frequency as when using the TDP limit = 125W. However, the Blend test runs at a higher frequency when using TDP limit vs current limit, indicating to me that the motherboard is allowing the CPU to draw even more current than 135A when handled automatically. Therein lies my concern. Is 135A-150A+ safe for this CPU? I don't want to be shooting myself in the foot undervolting to reduce heat only to be killing the CPU by pumping too much current.