diff --git a/man/3proxy.cfg.5 b/man/3proxy.cfg.5
index 383a77f..f4b446b 100644
--- a/man/3proxy.cfg.5
+++ b/man/3proxy.cfg.5
@@ -229,6 +229,17 @@ the filters see all of the data, nor does one ending or beginning TLS, unless
 the kernel does TLS for it both ways (\fBssl_ktls\fR). Available in builds with
 WITHSPLICE, the default on Linux.
 .br
+.B -b
+\fISIZE\fR[\fB,\fIPIPESIZE\fR] (for TCP services) read at most \fISIZE\fR bytes at
+once into a connection's buffer: less than the 16K it has, never more.
+\fIPIPESIZE\fR (Linux, with \fB-s\fR) makes the pipes of splice() hold that many
+bytes instead of 64K, from 4096 to 67108864, e.g. \fB-b,262144\fR: the
+system rounds it up to a power of 2 pages, and gives an unprivileged process
+no more than /proc/sys/fs/pipe-max-size (1M by default). A pipe that cannot
+be made so large is not used, and the data is copied. Larger pipes move more
+at once and take more kernel memory for each connection; 64K was as fast as
+larger ones in our tests.
+.br
 .B -C
  (for TCP services) a connection closed by any of the sides terminates the
 session, buffered data is delivered before the sockets are closed. By default
diff --git a/src/mainconf.c b/src/mainconf.c
index 390b95a..cb1407f 100644
--- a/src/mainconf.c
+++ b/src/mainconf.c
@@ -400,7 +400,16 @@ static int srvprepare(struct srvstart *s, int argc, char **argv){
 			srv->family = atoi(argv[i]+1);
 			break;
 		 case 'b':
+			/* -b[SIZE][,PIPESIZE] */
 			srv->bufsize = atoi(argv[i]+2);
+#ifdef WITHSPLICE
+			if(strchr(argv[i]+2, ',')){
+				long n = atol(strchr(argv[i]+2, ',') + 1);
+
+				if(n < 4096 || n > MAXPIPESIZE) error = 1;
+				else srv->pipesize = (unsigned)n;
+			}
+#endif
 			break;
 #ifdef STDMAIN
 #ifndef _WIN32
diff --git a/src/mainloop.c b/src/mainloop.c
index 62ee40e..1f297f6 100644
--- a/src/mainloop.c
+++ b/src/mainloop.c
@@ -620,13 +620,13 @@ static int cbway(struct cbmap *m, struct cbway *w){
 
 		/* what was buffered goes first: the pipe is read once it is
 		   through */
-		if(!inb && !w->wantbuf && w->left > w->inpipe && !m->term_r[w->src] && !end && w->inpipe < PIPESIZE &&
+		if(!inb && !w->wantbuf && w->left > w->inpipe && !m->term_r[w->src] && !end && w->inpipe < SRVPIPESIZE(param->srv) &&
 		    (rs->ready & (POLLIN | POLLHUP | POLLERR))){
-			if(pipe[0] < 0 && pipenew(pipe) < 0){
+			if(pipe[0] < 0 && pipenew(pipe, SRVPIPESIZE(param->srv)) < 0){
 				w->splice = 0;
 				return 1;
 			}
-			n = splice(from, NULL, pipe[1], NULL, (size_t)CBMIN((uint64_t)PIPESIZE - w->inpipe,
+			n = splice(from, NULL, pipe[1], NULL, (size_t)CBMIN((uint64_t)SRVPIPESIZE(param->srv) - w->inpipe,
 				w->left - w->inpipe), SPLICE_F_NONBLOCK | SPLICE_F_MOVE);
 			if(n > 0){
 				w->inpipe += n;
diff --git a/src/proxy.h b/src/proxy.h
index ed09130..04e2bee 100644
--- a/src/proxy.h
+++ b/src/proxy.h
@@ -614,11 +614,14 @@ extern struct commands commandhandlers[];
 #define SPLICE_TLSPENDING 2
 extern int (*splicetls)(struct clientparam *param, SOCKET s);
 /* what a pipe of splice() is given at most: 64K, what a pipe holds;
-   built with -DPIPESIZE=<bytes>, pipes are made that large */
+   built with -DPIPESIZE=<bytes>, or for a service given -b,<bytes>, pipes
+   are made that large, up to MAXPIPESIZE */
 #ifndef PIPESIZE
 #define PIPESIZE 65536
 #endif
-int pipenew(int p[2]);
+#define MAXPIPESIZE (64 * 1024 * 1024)
+#define SRVPIPESIZE(srv) ((srv)->pipesize? (srv)->pipesize : (unsigned)PIPESIZE)
+int pipenew(int p[2], unsigned size);
 #define mapsocket(a,b) ((a->srv->usesplice && !a->nosplice && !a->ndatfilterssrv && !a->ndatfilterscli)?sockmap(a,b,a->srv->usesplice):sockmap(a,b,0))
 #else
 #define mapsocket(a,b) sockmap(a,b, 0)
diff --git a/src/sockmap.c b/src/sockmap.c
index 3c8e82e..88e3532 100644
--- a/src/sockmap.c
+++ b/src/sockmap.c
@@ -35,18 +35,16 @@ ssize_t splice(int fd_in, loff_t *off_in, int fd_out, loff_t *off_out, size_t le
    and EBADMSG on some kernels */
 #define SPLICEREFUSED(e) ((e) == EINVAL || (e) == EIO || (e) == EBADMSG)
 
-/* A pipe for splice(), nonblocking, of PIPESIZE: -1 if there is none to be
-   had, or not of that size. */
-int pipenew(int p[2]){
+/* A pipe for splice(), nonblocking, holding size: -1 if there is none to
+   be had, or not so large. A pipe holds 64K as it is made. */
+int pipenew(int p[2], unsigned size){
 	if(pipe2(p, O_NONBLOCK) < 0) return -1;
-#if PIPESIZE != 65536
-	if(fcntl(p[0], F_SETPIPE_SZ, PIPESIZE) < 0){
+	if(size != 65536 && fcntl(p[0], F_SETPIPE_SZ, (int)size) < 0){
 		close(p[0]);
 		close(p[1]);
 		p[0] = p[1] = -1;
 		return -1;
 	}
-#endif
 	return 0;
 }
 
@@ -140,6 +138,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 
 #ifdef WITHSPLICE
  uint64_t inclientpipe = 0, inserverpipe = 0;
+ unsigned pipesize = SRVPIPESIZE(param->srv);
  int TOCLIENTPIPE = 0, FROMCLIENTPIPE = 0, TOSERVERPIPE = 0, FROMSERVERPIPE = 0;
  /* The client's data goes through pipecli, the server's through pipesrv.
     They belong to the connection: made when first needed, kept for the
@@ -361,7 +360,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 		/* each direction goes through its pipe if spliced, through its
 		   buffer otherwise; what was in the buffer before is sent first */
 		if(splicecli && inclientpipe && !inclientbuf && FROMCLIENTPIPE && TOSERVER){
-			res = splice(pipecli[0], NULL, param->remsock, NULL, MIN(PIPESIZE, inclientpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
+			res = splice(pipecli[0], NULL, param->remsock, NULL, MIN(pipesize, inclientpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
 			/* from a pipe holding data: the socket is full */
 			if(res < 0 && errno == EAGAIN && fiberblockfunc) fiberblockfunc(param->remsock, POLLOUT);
 			if(res >0) {
@@ -388,7 +387,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 			}
 		}
 		if(splicesrv && inserverpipe && !inserverbuf && FROMSERVERPIPE && TOCLIENT){
-			res = splice(pipesrv[0], NULL, param->clisock, NULL, MIN(PIPESIZE, inserverpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
+			res = splice(pipesrv[0], NULL, param->clisock, NULL, MIN(pipesize, inserverpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
 			/* from a pipe holding data: the socket is full */
 			if(res < 0 && errno == EAGAIN && fiberblockfunc) fiberblockfunc(param->clisock, POLLOUT);
 			if(res > 0) {
@@ -408,7 +407,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 			}
 		}
 		if(splicecli && !wantbufcli && fromclient>inclientpipe && FROMCLIENT && TOCLIENTPIPE && !SESSIONEND){
-			if(pipecli[0] < 0 && pipenew(pipecli) < 0){
+			if(pipecli[0] < 0 && pipenew(pipecli, pipesize) < 0){
 				/* no pipe to be had: copy instead */
 				allowcli = splicecli = TOCLIENTPIPE = FROMCLIENTPIPE = 0;
 				if(param->cliinbuf < CLIROOM) TOCLIENTBUF = 1;
@@ -425,7 +424,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 				continue;
 			}
 			errno = 0;
-			res = splice(param->clisock, NULL, pipecli[1], NULL, (int)MIN((uint64_t)PIPESIZE - inclientpipe, (uint64_t)fromclient-inclientpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
+			res = splice(param->clisock, NULL, pipecli[1], NULL, (int)MIN((uint64_t)pipesize - inclientpipe, (uint64_t)fromclient-inclientpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
 			if(res <= 0) {
 				FROMCLIENT = TOCLIENTPIPE = 0;
 				if(res == 0 && !errno) {
@@ -455,13 +454,13 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 					else if(++streakcli > splicestreak) wantbufcli = 1;
 				}
 				inclientpipe += res;
-				if(inclientpipe >= PIPESIZE) TOCLIENTPIPE = 0;
+				if(inclientpipe >= pipesize) TOCLIENTPIPE = 0;
 				needaction = 0;
 				continue;
 			}
 		}
 		if(splicesrv && !wantbufsrv && fromserver > inserverpipe && FROMSERVER && TOSERVERPIPE && !SESSIONEND){
-			if(pipesrv[0] < 0 && pipenew(pipesrv) < 0){
+			if(pipesrv[0] < 0 && pipenew(pipesrv, pipesize) < 0){
 				allowsrv = splicesrv = TOSERVERPIPE = FROMSERVERPIPE = 0;
 				if(param->srvinbuf < SRVROOM) TOSERVERBUF = 1;
 				continue;
@@ -475,7 +474,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 				continue;
 			}
 			errno = 0;
-			res = splice(param->remsock, NULL, pipesrv[1], NULL, MIN(PIPESIZE - inserverpipe, fromserver - inserverpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
+			res = splice(param->remsock, NULL, pipesrv[1], NULL, MIN(pipesize - inserverpipe, fromserver - inserverpipe), SPLICE_F_NONBLOCK|SPLICE_F_MOVE);
 			if(res <= 0) {
 				FROMSERVER = TOSERVERPIPE = 0;
 				if(res == 0 && !errno) {
@@ -505,7 +504,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 			    	param->nreads++;
 				param->statssrv64 += res;
 				inserverpipe += res;
-				if(inserverpipe >= PIPESIZE) TOSERVERPIPE = 0;
+				if(inserverpipe >= pipesize) TOSERVERPIPE = 0;
 				if(param->bandlimfunc) {
 					int sl1;
 					sl1 = (*param->bandlimfunc)(param, res, 0);
@@ -753,7 +752,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 //		}
 #ifdef WITHSPLICE
 		{
-			if(splicecli && fromclient>inclientpipe && !TOCLIENTPIPE && inclientpipe < PIPESIZE){
+			if(splicecli && fromclient>inclientpipe && !TOCLIENTPIPE && inclientpipe < pipesize){
 				if(!after){
 					fds[fdsc].fd = pipecli[1];
 					fds[fdsc].events |= POLLOUT;
@@ -781,7 +780,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
 				}
 				fdsc++;
 			}
-			if(splicesrv && fromserver>inserverpipe && !TOSERVERPIPE && inserverpipe < PIPESIZE){
+			if(splicesrv && fromserver>inserverpipe && !TOSERVERPIPE && inserverpipe < pipesize){
 				if(!after){
 					fds[fdsc].fd = pipesrv[1];
 					fds[fdsc].events |= POLLOUT;
diff --git a/src/structures.h b/src/structures.h
index e771dda..5b9ecbe 100644
--- a/src/structures.h
+++ b/src/structures.h
@@ -723,6 +723,7 @@ struct srvparam {
 	int usesplice;
 	/* the automatic mode's heuristics, -s[N]:MIN,STREAK,SMALL */
 	int splicemin, splicestreak, splicesmall;
+	unsigned pipesize;	/* -b,SIZE: what a pipe is made to hold, 0 PIPESIZE */
 #endif
 	int halfclose;
 	int udpauth;