GPU · SCAN · Radeon

SCAN RADEON

What it is. HYDRA's automatic tuning for Radeon graphics cards. It lowers the core voltage step by step under a real 3D load until the card is no longer stable, adds a safety margin, then raises the memory clock until errors appear. The result goes to RX-TUNER, and at the end HYDRA rates your chip.

Why use it. Finding the lowest stable voltage by hand means hours of trial and crashes. The diagnostic does it on its own, recovers from driver resets and resumes after a crash or restart. You get a ready profile: an undervolt or an overclock, depending on the preset.

Tab SCAN → GPU Load HYDRA Elemental2 · VANTA Result in RX-TUNER Updated 31 Oct 2026

NoteThis page covers Radeon RX 6000, 7000 and 9000 cards. GeForce cards have their own section, SCAN NVIDIA: its settings and stages are different.

Starting a diagnostic

Close games and other tuning or monitoring apps. CHECK CONFLICTS shows what may interfere.
Click SCAN in the bottom bar of HYDRA and choose GPU.
The first time, HYDRA asks to download the APP PACK with the HYDRA Elemental2 benchmark, which serves as the load.
In RADEON DIAGNOSTIC CENTER, choose the card and a preset, check the settings, and click the check mark.
On RX 6000 with a changed PowerPlay table, HYDRA offers to return it to factory first. Yes restores it with a driver restart; No keeps it for the run.
Leave the PC alone until the end. The LOGGING tab shows the progress; STOP cancels the run.

RADEON DIAGNOSTIC CENTER

1Graphics card. The Radeon card to tune. The fields below switch to its own limits. [Display] marks the card with a monitor; the benchmark runs on the chosen card either way.
2Preset. A quick starting point for the main fields, see the table below. After choosing it you can change any field.
3VRAM and CORE Test. How many times each check is repeated, up to 10. 0 skips the VRAM stage.
4ADDITIONAL POWER TUNE & TWEAKS. PowerPlay settings for RX 6000; greyed out on other cards. See the table below.
5FAN CURVE. The fan curve during the run. It starts as a copy of the Global profile of RX-TUNER.
6GPU SETTINGS. Start values and fixed limits of the run, see GPU SETTINGS.
7Buttons. Screenshot, reset to the preset defaults, start, cancel.

Preset	Goal
UV	An undervolt: the core clock limit stays at stock and the power offset at the lowest value the card allows.
DEF	The stock power limit with an automatic clock limit.
OC	The highest power offset the card allows with an automatic clock limit.

Every preset starts the voltage search 50 mV below stock.

GPU SETTINGS

Field	What it does
CORE VID	The core voltage the search starts from. RX 6000 and 7000: a voltage in mV, from 200 mV below stock up to stock. RX 9000: an offset from the stock curve, from −200 to 0 mV.
Core Max Freq.	0 lets HYDRA choose the clock limit. Any other value fixes it: on RX 6000 and 7000 a clock from 2200 MHz up to 500 MHz above stock. On RX 9000 the field reads Core Max Offs. and takes an offset from −500 to 1000 MHz.
Power Offset	The power limit offset in percent, in the range the card allows. On RX 6000 it goes up to 30 %: above the driver's own limit, HYDRA raises the limit in the PowerPlay table.
VRAM	The memory clock the VRAM stage starts from, in MHz. By default 140 MHz above stock on RX 6000 and 200 MHz above stock on other cards.
VRAM Timings	DEF for the default memory timings, FAST for AMD's fast timings. FAST can add speed but leaves less stability margin.

Set Power Offset as you will use it every day: the result is only as stable as the conditions it was found in.

ADDITIONAL POWER TUNE & TWEAKS

Field	What it does
Tweaks	Turns off one of the card's deep-sleep power-saving features. This can make the test more stable but raises idle power.
MVDD	The memory voltage of the highest memory state, from 1100 to 1500 mV. More voltage can help a high memory clock but adds heat.
VDDCI max	The memory controller voltage of the highest memory state, from 600 to 1000 mV. Leave the default unless you tune memory stability.
SoC Offset	The SoC voltage offset, from −100 to 0 mV; 0 keeps stock behaviour.

RX 6000 only. When these values differ from factory, HYDRA writes them into a temporary PowerPlay table and restarts the driver before the run, which takes about 20 seconds. After the run it returns the factory table the same way.

What the diagnostic does

Preparation. HYDRA turns off the overlay, resets the card to stock and, on RX 6000, applies the PowerPlay settings from the panel above.
CORE search. From CORE VID, every Elemental2 run that passes lowers the voltage by 5 mV, until a run fails or the card's lowest voltage is reached. A failure is a driver reset or a crashed benchmark. The memory stays at its stock clock during this stage.
Clock limit on RX 6000. With Core Max Freq. at 0 and Power Offset not below 0, HYDRA also raises the clock limit by 10 MHz whenever the card reaches it under full load. On RX 7000 and 9000 the clock limit stays fixed and only the voltage is searched.
CORE verification. After a failure the voltage goes up 10 mV, and the run repeats as many times as CORE Test says. Another failure adds 10 mV more. When it passes, 5 mV is added as a safety margin. A failure at stock voltage stops the diagnostic.
VRAM. If VRAM Test is above 0, HYDRA tests the memory with VANTA: from the VRAM value it raises the clock in steps of about 10 MHz until VANTA finds errors, the memory controller reports errors, or the driver resets. Then it lowers the clock by two steps and checks it as many times as VRAM Test says. Errors at the stock clock stop the diagnostic.
Result. HYDRA prints the result and the chip quality, and saves everything to the Global profile of RX-TUNER.

The result

The log ends with the final settings, the clock the card held, and a chip quality based on how far below stock the core voltage ended (DELTA). The heading says OVERCLOCKING results for the DEF and OC presets and UNDERVOLTING results for UV.

Chip quality	RX 6000 and 7000	RX 9000
PLATINUM	100 mV or more	50 mV or more
GOLD	75 mV or more	38 mV or more
SILVER	50 mV or more	25 mV or more
BRONZE	less than 50 mV	less than 25 mV

After the diagnostic

The core voltage, the clock limit, the memory clock and timings, and the power offset are saved to the Global profile of RX-TUNER and written to disk. On RX 6000 and 7000 the clock limit is the clock the card held in the last passing run; on RX 9000 it is the offset you entered. RX-TUNER applies the result while it is on.
On RX 6000 with PowerPlay changes, the tested table waits in SOFT PP EDITOR. It takes effect only after the Apply PowerPlay button on RX-TUNER.
The fan curve of the dialog is used only during the run and does not change your profiles.
A run that is stopped or fails saves nothing. If even the stock voltage or memory clock is unstable, the diagnostic stops: check the card and its cooling first.
If the PC crashes or restarts, Phoenix resumes the diagnostic after HYDRA starts again. It waits 30 seconds first: press STOP to cancel. It continues 10 mV above the interrupted voltage, or two steps below the interrupted memory clock.
Turn the overlay back on in SETTINGS if you use it.

Good to know

More CORE Test repetitions take longer but catch borderline voltages; use 1 to explore and more before you keep the result.
With VRAM Test at 0, the stock memory clock is saved together with the chosen timings.
If VANTA itself fails to run several times, HYDRA keeps the last memory clock that passed and marks the VRAM result as questionable in the log.
On RX 7900 and RX 9070 series cards the log may show GRBM CORE observe-only lines. They note a suspicious GPU stall for analysis and do not change the result.
The diagnostic tunes one card at a time. For another card, run it again and choose that card.

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