diff --git a/Utilities/Log.cpp b/Utilities/Log.cpp
index 02459db6f6..885bef4e97 100644
--- a/Utilities/Log.cpp
+++ b/Utilities/Log.cpp
@@ -4,15 +4,19 @@
 #include "sema.h"
 
 #include "Utilities/sysinfo.h"
+#include "Utilities/Thread.h"
 #include "rpcs3_version.h"
 #include <string>
 #include <unordered_map>
+#include <thread>
+#include <chrono>
+
+using namespace std::literals::chrono_literals;
 
 #ifdef _WIN32
 #define NOMINMAX
 #include <Windows.h>
 #else
-#include <chrono>
 #include <sys/mman.h>
 #endif
 
@@ -49,24 +53,25 @@ void fmt_class_string<logs::level>::format(std::string& out, u64 arg)
 
 namespace logs
 {
-	constexpr std::size_t s_log_size = 128 * 1024 * 1024;
-	constexpr std::size_t s_log_size_s = s_log_size / 2;
-	constexpr std::size_t s_log_size_t = s_log_size / 4 + s_log_size_s;
-	constexpr std::size_t s_log_size_e = s_log_size / 8 + s_log_size_t;
-	constexpr std::size_t s_log_size_f = s_log_size / 16 + s_log_size_e;
+	// Memory-mapped buffer size
+	constexpr u64 s_log_size = 32 * 1024 * 1024;
 
 	class file_writer
 	{
 		fs::file m_file;
 		std::string m_name;
+		std::thread m_writer;
+		fs::file m_fout;
+		u64 m_max_size;
 
 #ifdef _WIN32
 		::HANDLE m_fmap;
 #endif
-		atomic_t<std::size_t> m_pos{0};
-		std::size_t m_size{0};
 		uchar* m_fptr{};
 
+		alignas(128) atomic_t<u64> m_buf{0}; // MSB (40 bit): push begin, LSB (24 bis): push size
+		alignas(128) atomic_t<u64> m_out{0}; // Amount of bytes written to file
+
 	public:
 		file_writer(const std::string& name);
 
@@ -319,6 +324,17 @@ logs::file_writer::file_writer(const std::string& name)
 			fmt::throw_exception("Cannot create %s.log (error %s)", name, fs::g_tls_error);
 		}
 
+		// Check free space
+		fs::device_stat stats{};
+		if (!fs::statfs(log_name, stats) || stats.avail_free < s_log_size * 8)
+		{
+			fmt::throw_exception("Not enough free space (%f KB)", stats.avail_free / 1000000.);
+		}
+
+		// Limit log size to ~25% of free space
+		m_max_size = stats.avail_free / 4;
+
+		// Initialize memory mapped file
 #ifdef _WIN32
 		m_fmap = CreateFileMappingW(m_file.get_handle(), 0, PAGE_READWRITE, s_log_size >> 32, s_log_size & 0xffffffff, 0);
 		m_fptr = m_fmap ? (uchar*)MapViewOfFile(m_fmap, FILE_MAP_WRITE, 0, 0, 0) : nullptr;
@@ -328,45 +344,72 @@ logs::file_writer::file_writer(const std::string& name)
 #endif
 
 		verify(name.c_str()), m_fptr;
-		std::memset(m_fptr, '\n', s_log_size);
 
 		// Rotate backups (TODO)
 		fs::remove_file(fs::get_config_dir() + name + "1.log.gz");
 		fs::create_dir(fs::get_config_dir() + "old_logs");
 		fs::rename(fs::get_config_dir() + m_name + ".log.gz", fs::get_config_dir() + "old_logs/" + m_name + ".log.gz", true);
+
+		// Actual log file (allowed to fail)
+		m_fout.open(log_name, fs::rewrite);
 	}
 	catch (...)
 	{
 		catch_all_exceptions();
 	}
+
+	m_writer = std::thread([this]()
+	{
+		thread_ctrl::set_native_priority(-1);
+
+		while (true)
+		{
+			const u64 bufv = m_buf;
+
+			if (bufv & 0xffffff)
+			{
+				// Wait if threads are writing logs
+				std::this_thread::yield();
+				continue;
+			}
+
+			const u64 st = +m_out;
+			const u64 end = std::min<u64>((st + s_log_size) & ~(s_log_size - 1), bufv >> 24);
+
+			if (end > st)
+			{
+				const u64 size = end - st;
+
+				if (m_fout && m_fout.write(m_fptr + st % s_log_size, size) != size)
+				{
+					m_fout.close();
+				}
+
+				m_out += end - st;
+			}
+			else
+			{
+				if (st == -1)
+				{
+					break;
+				}
+
+				std::this_thread::sleep_for(10ms);
+			}
+		}
+	});
 }
 
 logs::file_writer::~file_writer()
 {
-	if (m_size == 0)
+	// Stop writer thread
+	while (m_out << 24 < m_buf)
 	{
-		m_size = std::min<std::size_t>(+m_pos, s_log_size);
+		std::this_thread::yield();
 	}
 
-	// Compress
-	z_stream zs{};
-	if (deflateInit2(&zs, 9, Z_DEFLATED, 16 + 15, 9, Z_DEFAULT_STRATEGY) == Z_OK)
-	{
-		auto buf = std::make_unique<uchar[]>(s_log_size);
-		zs.avail_in  = ::narrow<u32>(m_size);
-		zs.avail_out = s_log_size;
-		zs.next_in   = m_fptr;
-		zs.next_out  = buf.get();
-
-		if (deflate(&zs, Z_FINISH) != Z_STREAM_ERROR)
-		{
-			fs::file(fs::get_config_dir() + m_name + ".log.gz", fs::rewrite).write(buf.get(), zs.total_out);
-		}
-
-		if (deflateEnd(&zs) != Z_OK)
-		{
-		}
-	}
+	m_out = -1;
+	m_writer.join();
 
 #ifdef _WIN32
 	UnmapViewOfFile(m_fptr);
@@ -374,33 +417,45 @@ logs::file_writer::~file_writer()
 #else
 	::munmap(m_fptr, s_log_size);
 #endif
-	m_file.trunc(m_size);
 }
 
 void logs::file_writer::log(logs::level sev, const char* text, std::size_t size)
 {
-	// Adaptive log limit
-	const auto lim =
-		sev >= logs::level::success ? s_log_size_s :
-		sev == logs::level::todo ? s_log_size_t :
-		sev == logs::level::error ? s_log_size_e : s_log_size_f;
-
-	if (m_pos >= lim)
+	while (true)
 	{
-		return;
-	}
+		const auto pos = m_buf.atomic_op([&](u64& v) -> uchar*
+		{
+			const u64 v1 = v >> 24;
+			const u64 v2 = v & 0xffffff;
 
-	// Acquire memory
-	const auto pos = m_pos.fetch_add(size);
+			if (v2 + size > 0xffffff || v1 + v2 + size >= m_out + s_log_size)
+			{
+				return nullptr;
+			}
 
-	// Write if possible
-	if (pos + size <= s_log_size)
-	{
-		std::memcpy(m_fptr + pos, text, size);
-	}
-	else if (pos <= s_log_size)
-	{
-		m_size = pos;
+			v += size;
+			return m_fptr + (v1 + v2) % s_log_size;
+		});
+
+		if (UNLIKELY(!pos))
+		{
+			std::this_thread::yield();
+			continue;
+		}
+
+		if (pos + size > m_fptr + s_log_size)
+		{
+			const auto frag = m_fptr + s_log_size - pos;
+			std::memcpy(pos, text, frag);
+			std::memcpy(m_fptr, text + frag, size - frag);
+		}
+		else
+		{
+			std::memcpy(pos, text, size);
+		}
+
+		m_buf += (u64{size} << 24) - size;
+		break;
 	}
 }