diff --git a/test/bench/go1/fasta_test.go b/test/bench/go1/fasta_test.go
index dcb2d1055d9..bff056fa90c 100644
--- a/test/bench/go1/fasta_test.go
+++ b/test/bench/go1/fasta_test.go
@@ -4,9 +4,24 @@
 
 package go1
 
+import "runtime"
+
 // Not a benchmark; input for revcomp.
 
-var fasta25m = fasta(25e6)
+var fastabytes = makefasta()
+
+func makefasta() []byte {
+	var n int = 25e6
+	if runtime.GOARCH == "arm" {
+		// TODO(dfc) remove this limitation after precise gc.
+		// A value of 25e6 consumes 465mb of heap on 32bit 
+		// platforms, which is too much for most ARM systems. 
+		// A value of 25e5 produces a memory layout that 
+		// confuses the gc on 32bit platforms. So 25e4 it is.
+		n = 25e4
+	}
+	return fasta(n)
+}
 
 func fasta(n int) []byte {
 	out := make(fastaBuffer, 0, 11*n)
diff --git a/test/bench/go1/revcomp_test.go b/test/bench/go1/revcomp_test.go
index 9256164d76f..6b6c1e5772b 100644
--- a/test/bench/go1/revcomp_test.go
+++ b/test/bench/go1/revcomp_test.go
@@ -77,9 +77,9 @@ func revcomp(data []byte) {
 	}
 }
 
-func BenchmarkRevcomp25M(b *testing.B) {
-	b.SetBytes(int64(len(fasta25m)))
+func BenchmarkRevcomp(b *testing.B) {
+	b.SetBytes(int64(len(fastabytes)))
 	for i := 0; i < b.N; i++ {
-		revcomp(fasta25m)
+		revcomp(fastabytes)
 	}
 }