The i5-4670 does not have turbo boosting enabled by default.
The i5-4670 does not have turbo boosting enabled by default.
Set up a compact PC with the board from an HP Prodesk 400 G1 MT desktop. I installed an i5-4670 and it functions well except for turbo boost failure. Running benchmarks like Cinebench/Prime95 shows a maximum of around 3.4GHz (single core) and even higher single-core potential, but it remains stuck at 3.4GHz despite the expected 3.6GHz and 3.8GHz targets. Voltage stays steady at 1V, temperature reaches up to 45°C, yet performance doesn’t improve. I updated drivers, BIOS, checked options including turbo boost settings, reset CMOS, but XTU still reports Turbo enabled with high states (84W and 105W). No clear indication of CPU issue, but the board seems to limit output. Anyone have encountered this problem on an HP board? Could be a hardware limitation or firmware quirk? Any suggestions? Thanks ahead.
It seems the performance is likely managed by the exclusive motherboard, though you might not be missing much in terms of real gains.
I purchased the board from eBay since it was among the most affordable H81 boards with a 24-pin ATX design. Typical H81 boards from brands like ASUS or MSI usually cost $40 to $50, which feels quite low considering it matches the price of an A520. The compatibility sheet from HP lists both i5 and i7 processors and details their turbo capabilities.
Imagine how it would handle an i7 now... probably just another oddity? It’s still a bit confusing.
It seems your BIOS isn't configuring the CPU properly. If your processor only reaches 3.4 GHz, turbo boost should be turned off. There are several ways to disable it—Intel XTU only offers one method, so consider using ThrottleStop instead. Share some screenshots of ThrottleStop: main window, FIVR window, and TPL window. Also, include a photo of the Limit Reasons window when your CPU starts loading; it may display a reason for throttling turbo boost. If you provide detailed information, we might find a solution to adjust your CPU settings. On locked CPUs, enabling C states is important so the CPU can use the highest multipliers. Check if your BIOS has an option to turn C states on.
It seems Windows was acting strangely. I created a live Linux USB and ran the 7zip benchmark while watching scaling_cur_freq. Surprisingly, I achieved 3.8 on single and 3.6 on multi. This points to a Windows issue... I plan to reinstall it to check if it resolves the problem. Note: Throttlestop can properly set turbo to 3.6 allcore. Edit 2: It reverts to 3.4 during benchmarking. Throttlestop claims EDP limits, so the motherboard's VRMs are definitely problematic.