[BUG] "Detected no AVX2 support"

[sharkeylaser]

Hello! I just updated to "Hybrid_dev_2026.03.08-182859" and noticed the message "Detected no AVX2 support" in the logs. I don't recall seeing that before. My CPU is an Intel i7-5930K and it does support AVX2 (https://www.intel.com/content/www/us/en/...tions.html). I don't believe AVX2 can be toggled via BIOS, and it is shown as an instruction via CPU-Z (shown in the attached screenshot). I've uploaded the debug output in a zip file due to upload size restrictions. Let me know if there's anything I need to do on my end to fix! Thanks for your time!

[Selur]

The used code:

bool HybridMainWindow::cpuSupportsAVX2() const
{
    unsigned int ebx = 0;

#ifdef _MSC_VER
    int cpuInfo[4];
    __cpuid(cpuInfo, 0);
    if (cpuInfo[0] < 7)
        return false;

    __cpuidex(cpuInfo, 7, 0);
    ebx = cpuInfo[1];
#elif Q_OS_WIN
    unsigned int eax, ecx, edx;
    unsigned int cpuInfo[4];
    __cpuid(0, eax, ebx, ecx, edx);
    if (eax < 7)
        return false;

    __cpuid_count(7, 0, eax, ebx, ecx, edx);
#endif

    // Bit 5 of EBX in CPUID leaf 7 subleaf 0 indicates AVX2 support
    return (ebx & (1 << 5)) != 0;
}

should be correct, so I suspect it's some detection or preset glitch.

Does this also happen if you:
a. restart Hybrid
b. clear the tools cache?
c. reset the defaults

Cu Selur

[sharkeylaser]

Thank you for your response! That's very strange.
As for the questions:
a. Yes, restarted both Hybrid and my computer.
b. I'm assuming that is "Config -> Tools -> Clear all cached tool infos"? If so, then yes still happening.
c. Also yes after resetting to default.

[Selur]

Just to be sure: You are not running some VM, right?
If you run some antivirus software aside from Microsofts Defender, does it make a difference if you disable it?
(afaik. only sandbox software, malware detection, antivirus detection, benchmarking or over-/underclocking tools might interfere with the above code)

Cu Selur

Ps.: I added that code on 2025-05-13 and haven't changed it since then. (so every version after that has this code)

[sharkeylaser]

Correct, this isn't a VM. It's a dual-boot system, Windows 11 and Linux.
No other anti-virus running, just Windows Defender. Tried disabling that as well but no change.

Edit: just tried booting Windows with both refind and Microsoft's bootloaders, no change.

[Selur]

hmm,...
I created a Hybrid.exe for testing which uses:

#include <QStringList>
#include <QString>
#include <QByteArray>

#if defined(_MSC_VER)
#include <intrin.h>
#elif defined(__GNUC__) || defined(__clang__)
#include <cpuid.h>
#endif

static void cpuid(unsigned int leaf, unsigned int subleaf,
                  unsigned int &eax, unsigned int &ebx,
                  unsigned int &ecx, unsigned int &edx)
{
#if defined(_MSC_VER)
    int regs[4];
    __cpuidex(regs, leaf, subleaf);
    eax = regs[0];
    ebx = regs[1];
    ecx = regs[2];
    edx = regs[3];
#else
    __cpuid_count(leaf, subleaf, eax, ebx, ecx, edx);
#endif
}

QStringList getCpuInfo()
{
    QStringList info;

    unsigned int eax, ebx, ecx, edx;

    // Leaf 0 : Vendor + max leaf
    cpuid(0, 0, eax, ebx, ecx, edx);

    unsigned int maxLeaf = eax;

    char vendor[13];
    memcpy(vendor + 0, &ebx, 4);
    memcpy(vendor + 4, &edx, 4);
    memcpy(vendor + 8, &ecx, 4);
    vendor[12] = 0;

    info << QString("Vendor: %1").arg(vendor);
    info << QString("Max CPUID leaf: %1").arg(maxLeaf);

    // Leaf 1 : basic features
    cpuid(1, 0, eax, ebx, ecx, edx);

    info << QString("SSE: %1").arg((edx >> 25) & 1);
    info << QString("SSE2: %1").arg((edx >> 26) & 1);
    info << QString("SSE3: %1").arg((ecx >> 0) & 1);
    info << QString("SSSE3: %1").arg((ecx >> 9) & 1);
    info << QString("SSE4.1: %1").arg((ecx >> 19) & 1);
    info << QString("SSE4.2: %1").arg((ecx >> 20) & 1);
    info << QString("AVX: %1").arg((ecx >> 28) & 1);
    info << QString("FMA: %1").arg((ecx >> 12) & 1);

    // Leaf 7 : extended features
    if (maxLeaf >= 7)
    {
        cpuid(7, 0, eax, ebx, ecx, edx);

        info << QString("AVX2: %1").arg((ebx >> 5) & 1);
        info << QString("BMI1: %1").arg((ebx >> 3) & 1);
        info << QString("BMI2: %1").arg((ebx >> 8) & 1);
        info << QString("AVX512F: %1").arg((ebx >> 16) & 1);
        info << QString("SHA: %1").arg((ebx >> 29) & 1);
    }

    // CPU brand string
    char brand[49] = {0};

    if (maxLeaf >= 0x80000004)
    {
        unsigned int data[4];

        for (int i = 0; i < 3; ++i)
        {
            cpuid(0x80000002 + i, 0, data[0], data[1], data[2], data[3]);
            memcpy(brand + i * 16, data, 16);
        }

        info << QString("Brand: %1").arg(QString::fromLatin1(brand).trimmed());
    }

    return info;
}

=> https://www.mediafire.com/file/tluc424y8...st.7z/file (simply replace the Hybrid.exe with this one)
which should output something similar to:

CPU INFO:   Vendor: AuthenticAMD   Max CPUID leaf: 13   SSE: 1   SSE2: 1   SSE3: 1   SSSE3: 1   SSE4.1: 1   SSE4.2: 1   AVX: 1   FMA: 1   AVX2: 1   BMI1: 1   BMI2: 1   AVX512F: 1   SHA: 1

inside the normal log.
What does it show for you?

Cu Selur

[sharkeylaser]

Ah, yeah that seems to recogise it now!

CPU INFO:   Vendor: GenuineIntel   Max CPUID leaf: 15   SSE: 1   SSE2: 1   SSE3: 1   SSSE3: 1   SSE4.1: 1   SSE4.2: 1   AVX: 1   FMA: 1   AVX2: 1   BMI1: 1   BMI2: 1   AVX512F: 0   SHA: 0

[Selur]

Okay, but Hybrid still shows "Detected no AVX2 support" ?

[sharkeylaser]

Correct, it still shows that message, underneath the new one:

Finished startup, finished after 18.659s
CPU INFO:   Vendor: GenuineIntel   Max CPUID leaf: 15   SSE: 1   SSE2: 1   SSE3: 1   SSSE3: 1   SSE4.1: 1   SSE4.2: 1   AVX: 1   FMA: 1   AVX2: 1   BMI1: 1   BMI2: 1   AVX512F: 0   SHA: 0
Detected no AVX2 support,...

My apologies, I should have used clearer wording there.

[Selur]

Okay, will look into it and report back with a new test version in a bit.

Cu Selur