diff --git a/tinygrad/runtime/support/am/amdev.py b/tinygrad/runtime/support/am/amdev.py
index afe20ae64f..11bc670369 100644
--- a/tinygrad/runtime/support/am/amdev.py
+++ b/tinygrad/runtime/support/am/amdev.py
@@ -196,8 +196,8 @@ class AMDev(PCIDevImplBase):
     self.smi_dev = smi_dev
 
     # Memory manager & firmware
-    self.mm = AMMemoryManager(self, self.vram_size, boot_size=(32 << 20), pt_t=AMPageTableEntry, va_shifts=[12, 21, 30, 39], va_bits=48,
-      first_lv=am.AMDGPU_VM_PDB2, va_base=AMMemoryManager.va_allocator.base,
+    self.mm = AMMemoryManager(self, self.vram_size - self.reserved_vram_size, boot_size=(32 << 20), pt_t=AMPageTableEntry, va_shifts=[12, 21, 30, 39],
+      va_bits=48, first_lv=am.AMDGPU_VM_PDB2, va_base=AMMemoryManager.va_allocator.base,
       palloc_ranges=[(1 << (i + 12), 0x1000) for i in range(9 * (3 - am.AMDGPU_VM_PDB2), -1, -1)], reserve_ptable=not self.large_bar)
     self.fw = AMFirmware(self)
 
@@ -304,6 +304,7 @@ class AMDev(PCIDevImplBase):
 
     gc_info = am.struct_gc_info_v1_0.from_address(gc_addr:=ctypes.addressof(self.bhdr) + self.bhdr.table_list[am.GC].offset)
     self.gc_info = getattr(am, f"struct_gc_info_v{gc_info.header.version_major}_{gc_info.header.version_minor}").from_address(gc_addr)
+    self.reserved_vram_size = (280 << 20) if self.ip_ver[am.GC_HWIP][:2] in {(9,4), (9,5)} else (64 << 20)
 
   def _ip_module(self, prefix:str, hwip, prever_prefix:str=""): return import_module(prefix, self.ip_ver[hwip], prever_prefix)
 
diff --git a/tinygrad/runtime/support/memory.py b/tinygrad/runtime/support/memory.py
index b8c6179d48..14d88c13d9 100644
--- a/tinygrad/runtime/support/memory.py
+++ b/tinygrad/runtime/support/memory.py
@@ -176,7 +176,7 @@ class MemoryManager:
 
     self.boot_allocator = TLSFAllocator(boot_size, base=0)
     self.ptable_allocator = TLSFAllocator(round_up(vram_size // 512, 1 << 20) if self.reserve_ptable else 0, base=self.boot_allocator.size)
-    self.pa_allocator = TLSFAllocator(vram_size - (off_sz:=self.boot_allocator.size + self.ptable_allocator.size) - (64 << 20), base=off_sz)
+    self.pa_allocator = TLSFAllocator(vram_size - (off_sz:=self.boot_allocator.size + self.ptable_allocator.size), base=off_sz)
     self.root_page_table = pt_t(self.dev, self.palloc(0x1000, zero=not self.dev.smi_dev, boot=True), lv=first_lv)
 
   def _frag_size(self, va, sz, must_cover=True):
diff --git a/tinygrad/runtime/support/nv/nvdev.py b/tinygrad/runtime/support/nv/nvdev.py
index 400f8b958b..df870eac76 100644
--- a/tinygrad/runtime/support/nv/nvdev.py
+++ b/tinygrad/runtime/support/nv/nvdev.py
@@ -137,8 +137,10 @@ class NVDev(PCIDevImplBase):
     # 4           PDE0 (dual 64k/4k PDE, or 2M PTE)   28:21
     # 5           PTE_64K / PTE_4K                    20:16 / 20:12
     bits, shifts = (56, [12, 21, 29, 38, 47, 56]) if self.mmu_ver == 3 else (48, [12, 21, 29, 38, 47])
-    self.mm = NVMemoryManager(self, self.vram_size, boot_size=(2 << 20), pt_t=NVPageTableEntry, va_bits=bits, va_shifts=shifts, va_base=0,
-      palloc_ranges=[(x, x) for x in [512 << 20, 2 << 20, 4 << 10]], reserve_ptable=not self.large_bar)
+
+    # tail vram reserved for falcon structs
+    self.mm = NVMemoryManager(self, self.vram_size - (64 << 20), boot_size=(2 << 20), pt_t=NVPageTableEntry, va_bits=bits, va_shifts=shifts,
+      va_base=0, palloc_ranges=[(x, x) for x in [512 << 20, 2 << 20, 4 << 10]], reserve_ptable=not self.large_bar)
 
   def _alloc_sysmem(self, size:int, vaddr:int=0, contiguous:bool=False, data:bytes|None=None) -> tuple[MMIOInterface, list[int]]:
     view, paddrs = self.pci_dev.alloc_sysmem(size, vaddr, contiguous=contiguous)