Wednesday, April 7th 2021
Gear 1 can Lead to Performance Loss on Intel "Rocket Lake" 11th Gen Processors
In the course of our Core i5-11400F "Rocket Lake" processor review, we discovered that the Gear 2 memory mode has the potential to offer higher performance than Gear 1. The Gear 1 mode runs the memory frequency and memory controller frequency in 1:1 sync, while the Gear 2 mode runs them at 1:2, meaning that the memory controllers run at half the memory frequency, allowing you additional memory overclocking headroom. At lower, more stable, memory frequencies, it should be logical to use Gear 1. Our testing springs some surprising results.
Overall, a stock Core i5-11400F paired with DDR4-3733 MHz memory, was found to be 1.5% faster with Gear 2, when averaged across all our CPU tests, compared to Gear 1 at the same 3733 MHz frequency. Gear 2 was 3.42% faster in Cinebench R23 multi-threaded, and a staggering 6% in MySQL. Across rendering and media workloads that scale across all cores, we find Gear 2 faster by 1-3%. It's only with less parallelized workloads such as gaming, where we see Gear 2 lag behind Gear 1, though not by much. In our i5-11400F review, we show that by running your processor in Gear 2, you're making your memory controllers pull less power, freeing up power budget for the CPU cores, translating into the nT performance gains we see here. We discovered that the uncore can pull anywhere between 5 to 10 W more power in Gear 1 mode. This is valuable power eating into the already constrained power-budget of this 65 W TDP chip.
Read the Intel Core i5-11400F TechPowerUp ReviewThis behavior wasn't spotted in our launch-day i5-11600K and i9-11900K reviews; as the i5-11400F is our first Rocket Lake with a 65 W TDP. We expect the disparity between Gear 2 and Gear 1 at stock settings to only grow wider with higher core-count 65 W models, such as the Core i7-10700/F and the i9-11900/F. Gear 1 claws its way back to the top when you engage power limit overrides offered by motherboards. These overrides vary from motherboard to motherboard, but they generally free up more power budget for your CPU cores to sustain their boost frequencies better. For more data and commentary, be sure to catch our Core i5-11400F review.
Overall, a stock Core i5-11400F paired with DDR4-3733 MHz memory, was found to be 1.5% faster with Gear 2, when averaged across all our CPU tests, compared to Gear 1 at the same 3733 MHz frequency. Gear 2 was 3.42% faster in Cinebench R23 multi-threaded, and a staggering 6% in MySQL. Across rendering and media workloads that scale across all cores, we find Gear 2 faster by 1-3%. It's only with less parallelized workloads such as gaming, where we see Gear 2 lag behind Gear 1, though not by much. In our i5-11400F review, we show that by running your processor in Gear 2, you're making your memory controllers pull less power, freeing up power budget for the CPU cores, translating into the nT performance gains we see here. We discovered that the uncore can pull anywhere between 5 to 10 W more power in Gear 1 mode. This is valuable power eating into the already constrained power-budget of this 65 W TDP chip.
Read the Intel Core i5-11400F TechPowerUp ReviewThis behavior wasn't spotted in our launch-day i5-11600K and i9-11900K reviews; as the i5-11400F is our first Rocket Lake with a 65 W TDP. We expect the disparity between Gear 2 and Gear 1 at stock settings to only grow wider with higher core-count 65 W models, such as the Core i7-10700/F and the i9-11900/F. Gear 1 claws its way back to the top when you engage power limit overrides offered by motherboards. These overrides vary from motherboard to motherboard, but they generally free up more power budget for your CPU cores to sustain their boost frequencies better. For more data and commentary, be sure to catch our Core i5-11400F review.
43 Comments on Gear 1 can Lead to Performance Loss on Intel "Rocket Lake" 11th Gen Processors
Also can you try messing with the Ring Cache ratio? they could improve/degrade efficiency to some degree.
So let me get this straight.
If I buy a 11900K CPU, a top Z590 mobo, and 2 sticks of DDR4-4200 RAM, am I forced to run only in G1 in order to keep the 4200 speed on the RAMs??
So, which is it?? :)
That's why we posted this, because everyone tested on high-powered CPUs and came to the conclusion "Gear 1 is best"
All non-K RKL CPUs are affected, no point buying more expensive memory for Gear 1, unless you manually increase the power limit at the same time
What intel did with this series is a disaster imo, hopefully the new 12th Gen won't have this gear crap anymore.
Or will they...?