diff --git a/client/TracyDxt1.cpp b/client/TracyDxt1.cpp
index 6174ed17..eb7d8eb5 100644
--- a/client/TracyDxt1.cpp
+++ b/client/TracyDxt1.cpp
@@ -28,6 +28,14 @@ static inline uint16_t to565( uint8_t r, uint8_t g, uint8_t b )
     return ( ( r & 0xF8 ) << 8 ) | ( ( g & 0xFC ) << 3 ) | ( b >> 3 );
 }
 
+static inline uint16_t to565( uint32_t c )
+{
+    return
+        ( ( c & 0xF80000 ) >> 19 ) |
+        ( ( c & 0x00FC00 ) >> 5 ) |
+        ( ( c & 0x0000F8 ) << 8 );
+}
+
 static uint64_t CheckSolid( const uint8_t* src )
 {
 #ifdef __SSE4_1__
@@ -78,6 +86,86 @@ static uint64_t ProcessRGB( const uint8_t* src )
     const auto solid = CheckSolid( src );
     if( solid != 0 ) return solid;
 
+#ifdef __SSE4_1__
+    __m128i mask = _mm_set1_epi32( 0xFFFFFF );
+    __m128i l0 = _mm_and_si128( _mm_loadu_si128(((__m128i*)src) + 0), mask );
+    __m128i l1 = _mm_and_si128( _mm_loadu_si128(((__m128i*)src) + 1), mask );
+    __m128i l2 = _mm_and_si128( _mm_loadu_si128(((__m128i*)src) + 2), mask );
+    __m128i l3 = _mm_and_si128( _mm_loadu_si128(((__m128i*)src) + 3), mask );
+
+    __m128i min0 = _mm_min_epu8( l0, l1 );
+    __m128i min1 = _mm_min_epu8( l2, l3 );
+    __m128i min2 = _mm_min_epu8( min0, min1 );
+
+    __m128i max0 = _mm_max_epu8( l0, l1 );
+    __m128i max1 = _mm_max_epu8( l2, l3 );
+    __m128i max2 = _mm_max_epu8( max0, max1 );
+
+    __m128i min3 = _mm_shuffle_epi32( min2, _MM_SHUFFLE( 2, 3, 0, 1 ) );
+    __m128i max3 = _mm_shuffle_epi32( max2, _MM_SHUFFLE( 2, 3, 0, 1 ) );
+    __m128i min4 = _mm_min_epu8( min2, min3 );
+    __m128i max4 = _mm_max_epu8( max2, max3 );
+
+    __m128i min5 = _mm_shuffle_epi32( min4, _MM_SHUFFLE( 0, 0, 2, 2 ) );
+    __m128i max5 = _mm_shuffle_epi32( max4, _MM_SHUFFLE( 0, 0, 2, 2 ) );
+    __m128i rmin = _mm_min_epu8( min4, min5 );
+    __m128i rmax = _mm_max_epu8( max4, max5 );
+
+    __m128i range1 = _mm_subs_epu8( rmax, rmin );
+    __m128i range2 = _mm_maddubs_epi16( range1, _mm_set1_epi8( 1 ) );
+    __m128i range3 = _mm_hadd_epi16( range2, range2 );
+    __m128i range4 = _mm_add_epi16( range3, _mm_set1_epi16( 1 ) );
+
+    uint32_t vrange1 = _mm_cvtsi128_si32( range4 ) & 0xFFFF;
+    uint32_t vrange2 = ( 4 << 16 ) / vrange1;
+
+    __m128i range = _mm_set1_epi16( vrange2 );
+
+    __m128i inset1 = _mm_srli_epi16( range1, 4 );
+    __m128i inset = _mm_and_si128( inset1, _mm_set1_epi8( 0xF ) );
+    __m128i min = _mm_adds_epu8( rmin, inset );
+    __m128i max = _mm_subs_epu8( rmax, inset );
+
+    __m128i c0 = _mm_subs_epu8( l0, rmin );
+    __m128i c1 = _mm_subs_epu8( l1, rmin );
+    __m128i c2 = _mm_subs_epu8( l2, rmin );
+    __m128i c3 = _mm_subs_epu8( l3, rmin );
+
+    __m128i is0 = _mm_maddubs_epi16( c0, _mm_set1_epi8( 1 ) );
+    __m128i is1 = _mm_maddubs_epi16( c1, _mm_set1_epi8( 1 ) );
+    __m128i is2 = _mm_maddubs_epi16( c2, _mm_set1_epi8( 1 ) );
+    __m128i is3 = _mm_maddubs_epi16( c3, _mm_set1_epi8( 1 ) );
+
+    __m128i s0 = _mm_hadd_epi16( is0, is1 );
+    __m128i s1 = _mm_hadd_epi16( is2, is3 );
+
+    __m128i m0 = _mm_mulhi_epu16( s0, range );
+    __m128i m1 = _mm_mulhi_epu16( s1, range );
+
+    __m128i p0 = _mm_packus_epi16( m0, m1 );
+
+    uint32_t vmin = _mm_cvtsi128_si32( min );
+    uint32_t vmax = _mm_cvtsi128_si32( max );
+
+    uint32_t vp[4];
+    _mm_store_si128( (__m128i*)vp, p0 );
+
+    uint32_t data = 0;
+    int k = 0;
+    for( int i=0; i<4; i++ )
+    {
+        uint32_t p = vp[i];
+        for( int j=0; j<4; j++ )
+        {
+            uint8_t idx = IndexTable[p & 0x3];
+            p >>= 8;
+            data |= idx << (k*2);
+            k++;
+        }
+    }
+
+    return uint64_t( ( uint64_t( to565( vmin ) ) << 16 ) | to565( vmax ) | ( uint64_t( data ) << 32 ) );
+#else
     uint8_t min[3] = { src[0], src[1], src[2] };
     uint8_t max[3] = { src[0], src[1], src[2] };
     auto tmp = src + 4;
@@ -110,6 +198,7 @@ static uint64_t ProcessRGB( const uint8_t* src )
     }
 
     return uint64_t( ( uint64_t( to565( min[0], min[1], min[2] ) ) << 16 ) | to565( max[0], max[1], max[2] ) | ( uint64_t( data ) << 32 ) );
+#endif
 }
 
 void CompressImageDxt1( const char* src, char* dst, int w, int h )