Performance declines under heavy usage
Performance declines under heavy usage
Mobo: Asus Prime z790m CPU uses i5 14600k with Peerless Assassin cooler. It has 120 SE RAM and a 750W PSU. I’m facing problems with my newly assembled system. During CPU tests (like R23), the P-core multiplier decreases. Keeping it at 5300MHz causes it to drop to 5100MHz when cores reach full speed. At high loads, cores jump back up to 5300MHz during idle. I’ve adjusted the P-core multiplier to x54 and x55 with all cores synced, but the effect is minimal. Idle speeds stay around 5400MHz or 5500MHz (CPU-Z). R23 benchmarks plummet instantly to 5000MHz or 5100MHz. I set undervolt in BIOS to lower CPU temps—cores reached 95°C at full load, but after BIOS changes they stayed under 70°C. Previously, Cinebench was near 22,000; now it’s about 23,965. My BIOS settings include XMP I (RAM), fixed core voltage 1.20, CEP disabled, SA and CEP also off. If CEPs were active, R23 would be closer to 10,000. I’ve pushed PL1, PL2, and IccMax to their limits. Raising core voltage to 1.25 helped a bit but increased temps during high loads. Any suggestions? I’ve attached a HWmonitor screenshot showing p-cores at 5200MHz.
The motherboard's power delivery isn't particularly strong, which might explain why ASUS imposed a current limit of around 110A. It seems ASUS tends to obscure BIOS settings and VRM temperature data in software tools, making it hard to verify the issue. Another possibility is an AVX offset being enabled by default. I'm not sure why it's active, but some BIOS versions have this bug and can't be turned off—try adjusting it to -1 in the BIOS and check if Cinebench speeds up. HWInfo64 works better than HWMonitor for these kinds of readings.
I review the AVX configurations. The offset was configured as Auto. I switched it to "user specified: 0". Apart from that, I noticed the VR Out is 116A at 5200mhz. I believe this isn't related to a fixed ratio offset problem. As mentioned earlier: adjusting the P core multiplier to x54 will cause it to drop to 51 or 50 under heavy load.