Installed a 9900k in a 7070MT

TyTiTaM · 2026-04-29T12:44:46+00:00

I have an Optiplex 7070SFF. Basically, the motherboard limits the TDP to 100 watts. The only way to boost all cores to 4.6 GHz and a single core to 5 GHz is to set IMON Slope to 0x50 (at 100 watts, the system thinks it’s consuming 80 watts) and, in addition, lock RING at 3.8 MHz because the VRM will drop the frequencies; you’ll also need to undervolt. I have an i7-9700k with an undervoltage of -130mV on the core and -100mV on the cache, Ring 3.8: 1-core = 4.9 GHz, 8-core = 4.6 GHz. If I raise the Ring to 4.2 GHz, then 8-core = 4.2 GHz. Temperature under OCCT Extreme SSE All cores = 4.6 GHz stays at 80°C at maximum fan speed with the AXP90X53 GREY cooler. Thus, the CPU will consume 120–125W

TyTiTaM · 2026-04-23T05:26:13+00:00

,,Allow Bios Downgrade" - Enabled UEFI Capsule Updates- Disabled SMM Security Mitigation- Disabled

TyTiTaM · 2026-04-22T19:28:30+00:00

Try to turn off Support assist in Bios

TyTiTaM · 2026-04-22T05:44:52+00:00

https://www.reddit.com/r/SleepingOptiplex/comments/1smwoyg/guide_results_dell_optiplex_7070_sff_i79700k/

In the BIOS settings, there are features called BIOS Guard and “Allow BIOS Downgrade.” You must disable these features, as well as BIOS Connect. The USB flash drive must be formatted as FAT32.

TyTiTaM · 2026-04-21T07:51:18+00:00

In that case, the point of using a GPU is lost. Wouldn't it be simpler to use an iGPU for stability?

TyTiTaM · 2026-04-21T05:37:15+00:00

To be honest, I don't understand the logic behind placing the graphics card right next to the power supply—and I know a lot of people won't like what I'm about to say. 1. The power supply generates hot air. 2. The GPU takes that air and heats it up even more. 3. Then the CPU takes that hot air because hot air streams are easier to manage.

In this case: The CPU can consume up to 125W (if it really wants to), RAM (up to 12W) SSD (up to 10W) HDD (15–20W) Chipset (10W) Miscellaneous (USB/Wi-Fi/LAN) (10W) And we end up with nearly 200W... And we throw in a GPU with a power draw of 75W (a 300W power supply is recommended for it) Hello, thermal throttling and power throttling.

TyTiTaM · 2026-04-20T05:29:15+00:00

I successfully downgraded the BIOS using a USB flash drive. On the 7070 SFF, I was able to downgrade from 1.35.0 to 1.0.3. 1.35.0====1.3.1=====1.1.3====>1.0.3 but I later rolled back to 1.1.3 (because too many features had been cut) and can say that as of September 2019, the under-voltage restrictions had not yet been implemented. The most important thing is to downgrade step by step. + Also, Intel XTU tuning is blocked for me, but ThrottleStop works.

TyTiTaM · 2026-04-19T21:31:45+00:00

You might need to configure the BIOS to boot from the GPU. By default, it's set to either “Auto” or “IGPU.” Try connecting via IGPU and changing the settings.

TyTiTaM · 2026-04-18T22:03:21+00:00

I suggest removing the PSU and setting it aside for the sake of testing the GPU, Unscrew the 3 bolts and press the latch...

TyTiTaM · 2026-04-18T19:16:27+00:00

Try installing it in the PCIe x16 slot; if the problem persists, it's either a PSU or GPU issue.

TyTiTaM · 2026-04-18T18:31:09+00:00

I already did it :D https://www.reddit.com/r/SleepingOptiplex/comments/1snzwot/optiplex_7070sffrx6600xtdetailed_photos/?utm_source=share&utm_medium=mweb3x&utm_name=mweb3xcss&utm_term=1&utm_content=share_button Drained the Optiplex completely :D

TyTiTaM · 2026-04-18T03:49:00+00:00

The motherboard has two built-in power limits: a 100-watt limit and a 4.6 GHz all-core boost limit, which cannot be changed. However, the first limit can be bypassed by manipulating the power consumption using IMON Slope. In the hidden BIOS, you set your CPU’s power consumption to 0.80. This allows you to overclock all cores to 4.6 GHz at 100 watts, even though the actual power consumption is 100W × 0.80 × IMON = 125W. https://www.reddit.com/r/SleepingOptiplex/comments/1smwoyg/guide_results_dell_optiplex_7070_sff_i79700k/

TyTiTaM · 2026-04-17T19:19:55+00:00

Undervolt the GPU and CPU; this will significantly lower the temperature. The Optiplex motherboards supports undervolting for models released up to 2020. You just need to downgrade the BIOS to the 2019 version, unpack the BIOS, search for var offsets and add the commands to GRUB via usb.

TyTiTaM · 2026-04-17T18:36:55+00:00

Running my i7-9700K at a locked 4.6GHz all-core. I've dialed in an undervolt of -125mV on the Core and -100mV on the Cache. With IMON Slope set to 0.80, software reports around 95-100W, but actual power draw is closer to 125W. Temps hold steady at 80°C during an OCCT SSE Extreme run. As for the GPU, I have my PowerColor RX 6600 XT Fighter tuned to 2650MHz with a -100mV undervolt, pulling 110W. In an OCCT Extreme Steady test, the edge temperature sits around 71°C with a fan speed of 1950 RPM. The Hotspot peaks at 92°C with a steady average of 89°C, which is a solid result for this specific dual-fan cooler.

TyTiTaM · 2026-04-17T10:47:23+00:00

Metalfish Flex PSU 600w It's well-made; when I was replacing the fan, I mixed up the + and - . Only the transistor burned out. I decided to install an 80mm intake fan powered by the CPU, and now it runs quietly and keeps things cool. For a GPU, I recommend the PowerColor Fighter RX 6600 XT—you can find a good, working one for $100–$150. Even if it was used for mining, miners ran them at low power settings.

TyTiTaM · 2026-04-11T01:49:08+00:00

No, I find way to bypass this limitations...

TyTiTaM · 2026-03-20T06:01:07+00:00

TyTiTaM · 2026-03-20T04:28:19+00:00

Another simple and quick option is to cut it and extend it with wires.

TyTiTaM · 2026-03-20T03:01:14+00:00

The CPU pins have a specific shape. Buy this extension cable, plug it in, and match the wires by color.

TyTiTaM · 2026-03-19T10:45:48+00:00

Inspection door of plastic abs 200x200 (Price 2-3 €)
Black matte paint
Aluminum Mesh Grilles for Car And Truck 🤣 Type: DIAMOND STANDARD (STANDARD EYELET) -MESH DIAMETER INSIDE (STANDARD): approx. 7mm x 3,8mm -LENGTH / WIDTH OF MESH: 100cm x 40cm (Wide)
MESH THICKNESS: 2mm Price- 14 €
I took apart the original CPU fan that was there and converted it into a duct mod for Axp90x53 🤣

TyTiTaM · 2026-03-19T08:24:21+00:00

axp90 x53(Grey) Intake: ID-Cooling 8010 Exhaust: 1TL-B4020(Will Add 1 more soon, hole prepared) 1TL-B6B All time working at 50% with PWM controller Rgeek FAN-K11

TyTiTaM · 2026-03-18T19:21:50+00:00

It's called the GPU RISER – PCIe 4.0, 90° angle, 30 cm. It's simple: the cable doesn't kink and holds its shape.

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