[GSD-13331] XMX regression performance of Vulkan cooperative matrix extensions after 8531 driver & oneAPI MKL 2026.1

### Pre-submission Checklist

- [x] I am using the latest GPU driver version ([download center](https://www.intel.com/content/www/us/en/search.html#sortCriteria=%40lastmodifieddt%20descending&f-downloadtype=Drivers&cf-tabfilter=Downloads&cf-downloadsppth=Graphics))
- [x] I have searched for similar issues and found none

### GPU Hardware

Intel Arc A380

### GPU Detailed Information

PS> Get-WmiObject Win32_VideoController | Where-Object {$_.Name -like "*Intel*"} | Select-Object Name, DriverVersion, DriverDate, VideoProcessor, AdapterRAM, PNPDeviceID | Format-List

Name : Intel(R) Arc(TM) A380 Graphics
DriverVersion : 32.0.101.8531
DriverDate : 20260221000000.000000-000
VideoProcessor : Intel(R) Arc(TM) A380 Graphics Family
AdapterRAM : 2147479552
PNPDeviceID : PCI\VEN_8086&DEV_56A5&SUBSYS_60041849&REV_05\8&2724E0D0&0&00080000020A

### Driver Installation Details

Device Manager manual installation in order to keep latest firmware from latest driver 8974

### Windows Build Information

PS C:\Users\Nikos> Get-ComputerInfo | Select-Object WindowsProductName, WindowsVersion, OsHardwareAbstractionLayer | Format-List

WindowsProductName : Windows 11 Pro
WindowsVersion : 25H2
OsHardwareAbstractionLayer : 10.0.26100.1

### Actual Behavior

Hello.

It seems that the last good known Vulkan runtime is in the driver 8531, regarding full performance of XMX engine using cooperative matrix extension.

After that driver, even the latest one, drops performance to around 2/3 of 8531 as measured by `vkpeak `for `fp16-matrix `and `int8-matrix `microbenchmarks.

Did Intel drop performance of XMX engine for Vulkan coopmat on purpose or is it a bug ?

Are you going to restore max speed of Vulkan coopmat in the next driver ?

Benchmark results:

vkpeak
device = Intel(R) Arc(TM) A380 Graphics
driver = Intel Corporation / 101.8531

fp16-matrix = 25855.50 GFLOPS
int8-matrix = 51721.49 GIOPS

device = Intel(R) Arc(TM) A380 Graphics
driver = Intel Corporation / 101.8974

fp16-matrix = 16165.81 GFLOPS
int8-matrix = 32335.90 GIOPS

Worth mentioning, I have kept latest FW from 8974 driver and I have manually installed 8531 driver.

Also using latest oneAPI MKL offline installer 2026.1 I saw the same regression like Vulkan ICD which unfortunately is not restored even using 8531 driver.
It's independent.

I would definitely try older oneAPI versions like 2026.0 or 2025.3 if you provide me the installers since they are not easily found.

BR,
Nikos

### Expected Behavior

The coopmat extension of Vulkan and joint matrix & oneMKL should restore their full speed using XMX engine

### Reproduction Rate

Always reproduces - 100%

### Steps to Reproduce

Install 8531 driver and run vkpeak.
Then install any driver newer than that and run vkpeak.

See the fp16-matrix and int8-matrix results.

### Is this a regression?

- [x] Yes, this is a regression - functionality that previously worked is now broken

### Last Known Working Driver Version

8531

### First Known Failing Driver Version

_No response_

### API Call Logs

_No response_

### Windows Event Viewer Logs

_No response_

### Crash Dumps / Minidumps

_No response_

### Source Code / Reproducer

_No response_

### Command Line / Application Details

_No response_

### oneAPI Version (if applicable)

_No response_

### System Configuration

_No response_

### Screenshots / Video

_No response_

### Intel System Support Utility Report

_No response_

### Additional Notes

_No response_

No source file is named. Start by reproducing the comparison with vkpeak on the Intel Arc A380 using driver 8531 and a newer driver such as 8974, recording the fp16-matrix and int8-matrix results; then compare the Vulkan cooperative-matrix and oneMKL behavior. Done means the regression's cause is identified and the affected benchmarks regain their previous performance.

Written by the indexing model from the issue text.