X299-XE GAMING: EZ Tuning OC => Slow Ethernet Download Speeds

[Talcyndl]

This is a weird one for me.

I recently built a new machine. I'm running the ROG STRIX X299-XE GAMING motherboard with an i7-7820X, 16GB (2x8GB) of Corsair Vengeance 3000MHz LPX DDR4, and a Samsung 960 EVO 500GB NVMe M.2 SSD. I'm using the Corsair Hydro Series H100i v2 AIO cooler for the CPU. I even installed the little VRM cooling fan that Asus included in the XE version of the motherboard.

The machine runs cool and stable. BUT....

When I use the EZ Tuning overclocking utility within BIOS my ethernet download speeds drop significantly. I have Verizon FIOS gigabit service using their "Quantum Gateway" router. I'm directly connected to it using a good CAT 6 cable. Without the overclock, I get consistent 800+ Mbs, both up and down. If I use the EZ Tuning overclock, my download speeds drop to 100-150 Mbs. Strangely, my upload speed remains around 800+ Mbs even when overclocking.

This is completely repeatable and consistent.

The EZ Tuning automatic overclock settings are as follows:

(1) AI Overclock Tuner set to XMP

(2) DRAM voltages up to 1.35

(3) Core ratios increased to 43 (for most cores) and 46 (for Cores 1 and 7) .

(4) DRAM CAS# Latency to 15

(5) DRAM RAS# to CAS# Delay to 17

(6) DRAM RAS# PRE Time to 17

(7) DRAM RAS# ACT Time to 35

I've updated the Intel network driver to the latest version from Intel's site (since they don't seem to auto update). I haven't had the time to experiment with manual overclocking settings. I'm guessing that the DRAM timings are probably creating a conflict with the Intel drivers, but wanted to get some thoughts and ideas here before I continued to bang my head against the wall.

So, anyone have any thoughts?

[Raja]

Set BCLK to 100 MHz and test the Ethernet performance.

[Talcyndl]

Thanks Raja. That was the issue.

I ended up having to revert the BIOS to default settings though. The BCLK setting was grayed out (showing "101") after EZ Tuning applied its changes.

Once I was back at the default settings, I was then able to change some of the non-BCLK related things to achieve a nice overclock to both the CPU and DRAM.

Everything is working now.

I do wonder if this is a driver issue with the ethernet adapter that Intel should address....

[Raja]

Np.

It's due to BCLK increasing the speed of the associated bus.

[EaglezRock]

This issue is NOT fixed in BIOS 1602.

[JustinThyme]

EaglezRock wrote:
This issue is NOT fixed in BIOS 1602.

This is NOT a BIOS issue. This is a result of hardware connected to the same bus not liking the change in the BCLCK frequency and is well known across multiple platforms and multiple manufacturers. I doubled the BLCK to 200 and halved the multplier and it still works fine. 100MHz, 200MHz no worries. 101, 102 MHZ and other devices connecting to that bus work less than in a stellar fashion, on board NICs are the most vulnerable.

[orion33]

I'm having the exact same problem as this guy. I used the EZ overclock and it messed upgrade internet speed to where I'm only getting 20 Mbs when I should be running at 1 gig. I've changed all the settings back to default inside bios and it seemed to work for a second. So when I went to go test it again before I got off, and its back to the same slow speed... Please please please help